You could benefit from looking into medication and/or therapy, espeically if have health insurance. If not, a lot of therapy options outside of NA/CA/AA are available...perhaps some TDSers closer to you might know of stuff in your area. Crack destroys pretty much everyone who takes it for years, but a lot of Rx medication taken under the guidence of a doctor can help a person and will not turn against you. And you can get it from a pharmacy, not a crackhouse. If it's not for you then it's not for you (I'm not gunna preach here, as I consider myself depressed and yet not wanting to be on an antidepressant), but it's not a horribly dangerous thing to try. Same with talk-therapy.
Coming back to the parents house can make a person depressed. A lot of my friends have expressed this to me, and I had it hit me when I moved back for a few months in my twenties. That feeling of getting out of home when you're young only to find yourself back, with bad memories inbetween at that, can feel devistating. But dude, you're not even 21 yet...you've got PLENTY more youth ahead of you. I'm 5 years older than you and don't feel much older than I did at 20. It might seem intimidating aging, but your 20s take A WHILE to get through and there's plenty of time for fun, change and growth.
And ya, I know about the memories of crackhouses and how they can be disturbing. I've only been in two (one the night I binged on it and another just, well, I won't go into that...). I saw things that I still think about. I nearly got seriously fucked-up and carjacked when exiting the first one...and just the sadness and loss of potential that I felt in such places. I'm guessing you might have a bit of Post Traumatic Stress Disorder (PTSD) from the whole crack experience, which is completely understandable. It's probably a very uncomfortable thing to talk with people about in real life, but a therapist probably could help you develop ways to help deal with those memories and move forward from them; not drown in them.
That fear could be a blessing-in-disguise

And you will make it dude.