I lived for 2 years in El Paso off plasma and food stamps... Keep your expenses down and it's actually very easy...
For example, I pay about $460 to live here including the cable. If I got a gf to move in, I could survive on $300/month in money and I would get food stamps for sure, plus my utilities would be paid. Plasma and odd jobs could easily cover the $300. Heck, I've seen 4+ people living in an apartment this size before.