I didn't read much through the other comments, I read some, but there were so many... So forgive me if this is has already been suggested...
Can you fight back at all? There are many reasons that people act like this... Maybe he's got issues and he's taking it out on you (not an excuse), maybe he just doesn't like you and wants you to leave, or maybe he's just doing it because he can.
If he just doesn't like you, and that's his shitty way of showing it, try talking to him, ask nicely if he could just try to tolerate you until you're able to get out, and that you'll start looking immediately.
If he's just doing it because he can, defend yourself with a weapon, unless you believe he could easily just overpower you and still assault you.. But honestly, even a tap on the top of the head with an aluminum bat hurts, pretty sure you could put him on the ground begging you to stop.
If facing your bully in any way just isn't an option, then leave. It's rough, but man, living on the street sounds better than that.. I've slept under a bridge and got my meals out of the dumpster behind the Casey's, and I'd much rather do it all again than be constantly in fear of physical harm. Maybe you could even crash on a friends couch or something?
Some places also have temporary housing similar to a battered women's shelter, but for anyone (if I've mis-assumed and you're not male, seek out a battered womens shelter), which is ugly and not a fun place to stay, might get some lice or be sleeping with bed bugs, but it'd be better than under a bridge by the train tracks.
If you'd like to take a legal route, record it. Possibly hide a camera and let it catch it naturally without him knowing... If you sit at a PC and he bothers you from there, set up and hide a webcam. Taking note of everything he does as others have suggested isn't going to help. Even if you write it all down, it's your word vs his, you need outstanding proof. You mentioned funds, but you can probably find a cheap webcam, or borrow equipment from a friend?
