Unfortunately, going from happy to deep depression in a very short period of time (minutes), really does add to the clinical side of things. Even if it may not seem chronic or like "real" depression that other people get, it can be, and any further question about that should really be to a doctor - yeah, it can be difficult, but it'd help.
Yeah, parents you love is a big thing. Fear of dying... well I've known a lot of people a lot, lot more messed up than me. Fear of death is not what kept them going, it would definitely be really low on their list of what kept them alive. Not to undervalue that, but I would think it's not entirely uncommon... I personally think a greater portion of people are afraid of how they die rather than if they die, though I think we'd all prefer to not worry about either for most of our lives.
As for me, what helped was that I'm an extremely rational person at heart with a idealistic streak, so no matter how bad things got I could never convince myself things would never get better. I'm good at reasoning, and my idealism refuses to let me to settle my day without believing that things possibly, regardless of the chance, could get better.
As for material changes... it's a bit personal but what the hey: I was in a dead-end job and played online video games a bunch, had a few pretty good online buddies I knew. Things were getting bad, one of them complains that their roommate was moving out soon and they didn't know how they'd get by without one helping out, and I was desperate. I was willing to drive 3000 miles just to get out of my job and take a risk on the other side of the country.
Told my mom, and she didn't like the sound of moving in with someone I didn't really know. However she and her husband (who didn't rent/own, they lived by "sitting" other peoples houses while doing web development and barely scraped by) also happened at the same time upon a situation where they were going to watch someone's house for 6 months, only 2700 miles away, and I might as well come with them.
Oh boy, no, things didn't go as planned. I quit my job, and a few days before I was to leave there... they called me and told me the client had misrepresented their house, it was more of a garbage dump than a place to sleep.
And yet, somehow another place was found, other people in the same area had rooms in their big expensive house they could put us in for 5 months, and after that web work picked up and we ended up another 2000 miles away in yet a different direction, in cars that we had no clue would make it.
Yeah, it's kind of unbelievable. That's why I say: you don't know what the future holds. Sometimes it's crap for a very long time, and doesn't seem like it'll ever end.
And then, suddenly without warning, it improves. Yeah, it's still not fantastic. But it's so much more manageable. And if you had suggested to me I'd be driving across the country twice in the span of a couple months, and that'd save me from going off the deep end due to a job that was chipping away at my life, making the doctor say: "Because your so young, I'd like to wait a couple weeks and then take your blood pressure again before officially stating your in stage-1 hypertension," I wouldn't have believed it.
Don't get me wrong: a lot of bad things happen. And I have to look at some of them and go: you know, I could have forseen this, because I took a particular gamble in life hoping for a good outcome on bad odds. This too was a gamble.
If you ask me as to what I would do specifically in the past, if I could do it over again though, to improve my situation, I'd say: learn sooner in life that working for anyone other than yourself is stressful, and find a way to make money in life working for yourself. Failing that, at least be the kind of person that can enjoy working for others.
Oh, and my career path, the one thing I'd do more than anything else, is now something that I thought I was absolutely terrible, horrible at in school. And I was a A/B student. That's why I want to end again with: find something you love. Even if you can't (yet) feed yourself doing it, find something to love and work at it.
I guess I can think of one more thing: don't worry about timetables. There are things that would take years to learn and get around to doing, when the immediate concern is the money and accomplishment needed today. I thought that day after day for a while. And then one, two, three years later I sat there going: wait what? I could have finished learning/doing THAT by now, and there's been no progress when there could have been. So don't worry that something is going to take 3,5, or more years to start paying off. Because you'll still be there in 3,5+ years later, thinking that it'd still take 3,5+ years.