I 100% agree with Mafioso. My own journey has taken me all over the map, emotion-wise and in terms of how I feel about the world. As a kid I felt pretty idyllic about the whole thing, I was unaware of the terrible problems affecting society. But by the time I was your age, about to graduate college, and also at various times afterwards for my entire twenties, I felt rather like you did, depressed, overwhelmed about the state of the world and the future, full of pain and anger at those responsible. I turned to opiates to numb it and by the time I was 28, 29 years old, I had been addicted to opiates for almost 10 years, and there were several other factors in my life that also contributed pain, and I was constantly having fantasies about killing myself... I fully hated myself AND the world. I wasn't quite to the point of actually intending to do it but I think it was only a matter of time before I got there. I felt like the entire world was shit, and everyone sucked. I wished it would burn and we could stop plaguing this beautiful planet with our collective psychopathy.
Then a few things happened. I got off opiates finally (via ibogaine, incidentally), I got out of my extremely toxic marriage, and I started playing music again and spending time with my friends. And something really amazing happened - I had a change in perspective. Suddenly I didn't have two huge sources of pain in my life (that marriage and opiates) filling me with anxiety and sadness and fear. I also had something back that brought a lot of meaning to my life and personal fulfillment and pride - music. And as I put myself back out there in the world, I started to realize that there are a whole lot of great people worth knowing who are good. I already lived in a place where the people are generally cool and there's a good community, there are places like this all around (a lot of them out Western USA but there are plenty of places in the US and elsewhere). I started to build a positive, uplifting community of people I can relate to and who can relate to me.
And before long, even though I am of course still aware of the terrible things about humans and that are going on in the world, my local world started to become a very good, positive place, a place where I can make a difference and I do. This has led me to feeling good as long as I don't dwell too much on the news and stuff like that. I am a happy person, I have struggles of course but I look forward to waking up every day and I spend a lot of time doing things I feel good about and that other people feel good about. I'm not gonna save the world, but I realized no one person can, and literally the only thing we can do (aside from getting deeply involved in activism) is try to be the best people we can be for those around us. Then we make things better for those people, who in turn are more able to do the same for their world. In essence, I changed my perspective on my situation and at the same time increased my participation in the world around me. I find now that, instead of constantly being reminded of the negative, and finding myself noticing all the little bad things happening throughout my day, I am more often reminded of the beauty in humans and the world, and noticing the little good things throughout my day, and oftentimes not even choosing to identify what I might have thought of as evidence of how the world is shit (such as, for example, "that fucker cut me off, what a dick, of course that happened to me, fml" instead being interpreted as "Whoa, careful man. Alright glad nothing happened").
Hopefully that helps in some way. It took purposeful work, and I always wonder how much the ibogaine helped facilitate this because it's the nature of the way I felt suddenly out of nowhere, immediately after the experience (which was also when I suddenly felt like I had no desire for opiates for the first time in 10 years). I think it just gave me insight, though. Because it definitely takes work to maintain my positive state of mind. You might think I'm ignoring the bad stuff, but I'm not. Some days I feel overwhelmed by it, still. It's just a decision I've made to not dwell on what I can't change. it's a smart survival strategy, not a denial. It does no one any good, least of all me, to dwell on stuff I can't change. So instead I choose to focus on what I can change. I believe anyone can do that, it just takes practice and it also takes action.
It might not sound related, but working out regularly (daily cardio and also strength training a few times a week - or at least as much as you can fit in) and getting in shape help so much with everything. That's another thing I started to do after I got off opiates, and it helped with feeling good (endorphins - this is a big help, trust me), and feeling confident/attractive/powerful. In fact the last year and a half or so I've really let the exercise slack and I feel the difference big-time, I am noticeably less happy and more anxious as a baseline.