This is the right place where to find failure experts who "feel" just like you. Never mind quiting the $i¢k 'n $ad realm, simply avoid mirrors...
I'm curious, if that's how you feel why do you choose to associate with failure experts?
I can't help but be reminded of an old idiom that centers around the company we choose to keep....
As far as OP goes, I'll throw it out there for the umpteenth time-- you'll struggle with stopping your weed habit for as long as you neglect to replace it with something else.
For a lot of people, weed is the boredom killer. When you're bored as fuck, you just have a quick session and *BOOM!* all of a sudden you're content despite facing the same situation that left you feeling bored prior to getting high.
Please don't get offended at the simplification but, my guy, you need a hobby or two. Woodworking, programming, just reading books that you can get lost in, gardening, mycology.... It doesn't matter what, you need SOMETHING to fill the void that you've been stuffing ganja into for god knows how long. You'll never successfully quit if you spend all of your conscious willpower thinking about how you quit and even though you want to you can't indulge anymore.... like, it's doable but that's a great way to stress yourself the fuck out. You need to find a way to stop using while picking up a hobby that exercises your mind enough to make you not want to CONTINUE using.
I'm admittedly being a little blunt because I've responded to countless threads like this over the years. If you'd like me to expand or have any other questions you think I might be able to answer, though, feel free to ask.
I feel like this may be counter-productive but it's worth a shot-- as far as your sleep habits go, I think you should look into melatonin as a nighttime sleep aid.
It's not healthy to use long-term but for 1-3 weeks? I think you'll be okay.
As far as melatonin goes, however, the lower the dose the better. They sell pills upwards of 10mg, but you might find yourself surprised when you discover that 0.5mg works equally as well and doesn't leave you with a strange hangover upon waking. It's also good to remember that it won't knock you out-- melatonin just makes it easier to drift into sleep once you're ready to lie down and end your day.