Hey Bro. The post about volunteering your time is a good place to start. Training consistently is hard ass work, both mentally and physically for anyone, even if you're not doing it professionally. Diet and a somewhat consistent lifestyle will definitely be to your benefit.
My .02 worth would be to get some kind of relatively stable income, whether it be fast food, stocking shelves, janitorial, whatever, and build from there. The reason I say this is that injuries WILL come, and you will definately need a place to crash without the added BS of street life and homelessness.
Not trying to be preachy, just trying to help.