I would not move out until she hands you the check for your part of the house. If she can't do that until May or June, I would not move until then. Once you move out you have little leverage to make her pay you.If she wants it that badly she will come up with the money.
As for buying a new house, talk to a mortgage broker first. You will probably find that you have to jump through some hoops since you were self-employed and your income wasn't that great (they won't count your new income until you've been working there for a while).
Take your time and find an appropriate rental for now. Don't leave the house though without a check for your share.
