i really do not know what the best law school you can get into, but you might surprise yourself -- not too many people have gone through your situation. as the other poster mentioned, go ahead and check your chances on the lsac calculator, and go from there.
and even if you do not know any of your professors, try your best to get one from a professor that you got a decent grade from. even if it is kind of bland, i think most schools take three recommendations, and i am sure your other recs will speak highly of you.
and yes, your experience qualifies as an excellent ps topic. don't make it whiny, though. try to focus on the what you gained from the experience, and how your determination helped you get through it.