From a philosophical standpoint, it is entirely hedonistic- which in my experience is devoid of meaning and will only lead to vanity and emptiness, which ultimately leads to this type of mindset. Ths real question posed here is "how can I experience the greatest amount of pleasure while facing the least amount of consequence", as OP stated that he's experienced success and other pleasures in life but in comparison, they aren't close to enough to the point of considering suicide. Assuming OP isn't trying to deceive or in denial, this is essentially a question of "how can I live a life in which I experience the greatest amount of pleasure humanly possible, regardless of consequence so long as it is painless to me?"
I am not attempting to judge OP's integrity, just analyze the philosophy driving the thought in as dry manner as possible.
I've tasted the slow burn pleasures life has to offer, and I have to say they don't seem worth it to me simply to live "longer". A short, intense, orgasmic life followed by a sweet painless death seems like the ideal way for an organism to exist. I feel a combination of things when I think about this: relief, guilt, fear of what my family and friends will think. Nobody will understand. Nobody. They won't get that I was happy.
This statement demonstrates that OP is aware that his actions will likely negatively affect others- particularly the fact he says he feels guilt and fear of what his family and friends will think. However, this statement is also very self-centered, only stopping to consider what the people who care about him will think- and the following statement gives me the impression that his concern is largely driven by a desire to protect his legacy after he's passed. There is no expression of how his actions will impact those that love and care about him beyond what they will think, seemingly about him. As if the narrative that he killed himself out of misery/depression is more concerning than the sadness and grief his family and friends will fill, and the inevitable fall out on their lives. It's essentially trading personal pleasure for other's misery. You get the time of your life once and for all, they get to deal with the loss. But hedonism is never concerned about anyone that won't bring it more pleasure, and I say this from experience being equally self indulgent.
There are many ways that this can be discussed, but I'd like to focus on the pleasure/pain aspect. I'd be lying if I said I hadn't had very similar thoughts myself, but the truth is that life is already limited and very short, so if you aren't trying to escape something what is it that you are trying to accomplish, aside from essentially the most grandiose form of masturbation... I mean it's literally not that much different than tying a rope around your neck to the point where you orgasm as you're approaching death. Except you get caught with a needle in your arm rather than your limp biscuit.
So this leads me to my next thought- if one isn't trying to escape anything yet is still considering ending it all for the ultimate orgasm... I have to question how OP defines "happy". In my mind, if one is truly happy, then one would try to survive at all costs. This is because I don't define happiness as simply as having a smile on my face and basic needs met. For me, true happiness has always been fleeting and is something that is pursued more often than experienced. It takes a lot of work to be happy- you have to maintain relationships and even then the bulk won't last, and not for lack of effort. You have to wake up every day and discipline yourself to do things that will better you even though they aren't desirable to do. Most spend the bulk of their time working jobs they probably didn't even know existed when they were kids and people are asking them "what do you want to be when you grow up", which is generally asked and answered in a superficial manner. It isn't "what brings you joy in life?", the question is basically "what occupation do you want to have within this society when you grow up?" Which personally makes me want to escape not only the monotony of working most jobs but also the superficial empty culture hyper focused on personal gain, generally in the form of money. And doing so in a way that is not only painless but euphoric sounds too good be to true.
But as soon as a step out of my hedonistic mindset, the act suddenly appears extremely selfish as most suicides leave many with pain that lasts a lifetime. So although you remove your pain, you are actually inflicting more pain onto the rest of the world. And to do so all in the name of having one mass euphoria- not trying to escape pain or remove burden from loved ones... well I can't see how it can be viewed as anything other than complete hedonism with almost a touch of sadism, unless absolutely no one will be negatively impacted by your action.. which seems hard to believe could be true of anyone with a family.
So then in conclusion, I would have to say that OP's definition of happiness isn't a very good one, as trading death for one last pleasure that wion't even be able to be fully realized because you won't be conscious for much of the experience. It's not much different than jumping off a cliff with no parachute for the thrill of the fall down. It benefits no one except you for the last few brief seconds of your life and leaves everyone else to handle the pain of loss, etc. Although one could scientifically break down happiness to a chemical level in the brain, I think it is a pretty big oversimplification. I personally don't have a solid definition of what happiness means to mean, and it's constantly changing with age, but the one constant is love. Not just romantic love, but when you care about someone more than yourself and that care is reciprocated. That to me is what makes life worth sticking it through all the ups and downs, and keeps me fighting to hold on even in my lows because I know there's people who would be much more than just sad. Watching and listening to the family and friends of people who have committed suicide makes it apparent to me that their pain will far outlast any bit of pleasure OP would get from proposed OD.
So to truly conclude entirely from a philosophical perspective, OP is trading short lived euphoria that can never be realized by OP, for the sorrow of anyone that actually cares about OP- which will be realized by each individual. The pain inflicted would only be in OPs attempts of achieving more pleasure, if it's true OP is happy and not trying to escape. It is ultimate hedonism.
From a non philosophical standpoint, I'd ask what's happening in your life right now? How do you define happiness? What types of things make you happy? Then I'd probably ask why all those things aren't worth sticking around for. And I may even agree that those things aren't worth sticking around for. I know for myself I've had to stop and ask myself what does happiness even mean to me? Lately it's something I do multiple times a day, or even all day some days if my mind isn't preoccupied. This could be completely different for you, but I've come to the sad realization that I actually gave up my happiness years ago for what I thought was a "better" happiness. To put it bluntly, I either walked away or destroyed pretty much all the meaningful relationships in my life up in pursuit of hedonism. Money sex and drugs. Nothing else was worth my time and if it was getting in my way of those 3 things or slowing me down at all, it needed to be cut out. Well over a decade into that mindset and I'm finally beginning to realize the depths of consequence. From a superficial point of view, I should be happy- I should be far more than happy, the me of 5-10 years ago wouldn't be able to comprhend the depths of my emptiness. I've spent a lot of time looking for someone or something to blame, but I've come to realize I've can't blame anyone but myself for chasing vanity.
Ultimately, there is no meaning in life other than the ones you choose to apply to it. All pleasures are fleeting, even life itself is. For me, it's about discovering and pursuing the pleasures that don't leave you with regret but instead continue to fuel your passion for life. I can't pretend that I have all the answers or any at all but when I look around and see people enjoying the most simple of things, well, I start to wonder if the problem hasnt been my perspective causing me a lot of my pain.
