Hey man! Seriously don't do it. Try to call someone to talk it out:
http://ptsdusa.org/get-help/hotline-crisis-numbers/
https://www.reddit.com/r/SuicideWatch/wiki/hotlines
Like I said before, so many things go wrong in this hobby, so it has to be expected. Everyone of us has had so many issues and some quit and some stick around and just keep building and building and replacing continuously to stay in the hobby. Honestly, I think the videos online lie. The hobby really isn't mostly about flying. It's 85% build, repair, charge batteries... and maybe 15% flying. That's unless you buy a Phantom or something else that does the flying for you. But even then, you still may crash. My co-worker got a Phantom 4 and had two days of good flying, then smashed it into a concrete wall and it fell straight down into a huge puddle of water. In this hobby, you're guaranteed to have a lot of what most people look at as setbacks. I think the ones who stay with the hobby look at them as challenges, experiences, etc.
Either way, getting disappointed over crashing/losing your quad is no good reason to shoot yourself because those things are something that everyone experiences in this hobby. Sometimes I think I want to get into buggies or something that doesn't leave the ground so I don't have to worry about all the things that come with flying quads. That might be a better route for you. You'll might still crash, but it won't be as bad. Or just buy super cheap quads and/or build something super cheap so you don't have to worry when something goes wrong. Even if you lose it, you'd still have your biggest investment in your hands (your tx) and you can just rebuild and you won't be out that much money (comparatively to a more expensive build).
Either way, I know you're not in a good state of mind, but I can't think of one good reason to let a disappointment from this hobby be worth shooting yourself. I know you have a lot of other stuff built up that almost none of us would be able to understand or comprehend, but some things take a lot of time to battle and resolve. Even though you're having a hell of a time now, you have to just take one breath at a time and chip away at the things that are causing you to hurt and suffer. Again - I would have no way of comprehending what you've been through, but there are certainly people who have been through a lot worse and made it through to a point where they were happy and content and had things under control. And I'm sure when they hit that point, it was the greatest feeling imaginable. I'm a true believer that people's appreciation for happiness is even higher if they've been through tough times that they didn't think they'd make it through.
I know things don't look very bright right now, but the first step is really to just get the underlying issues out on the table and to just battle through them so you can take control of your emotions and feelings. I really hope that you can find someone to talk to that understands what you're going through. It will be a long journey, but in the bigger picture, you have so much more life to live, so the struggle will certainly be worth it if you just fight through the healing process.
Sorry if any of this came off as cheesy or cliche, but I really mean it.
Mike