Lots of questions, a few answers:
A.) Yes, move on. Pack up all your work and put it in a safe place.
B.) Learn from it. In the future, all of the equity and administrative decisions should be made and agreed upon before writing any lines of code.
C.) While it might be satisfying to take your work and launch yourself (or hit him with a free service), think hard about it, and definitely consult a lawyer. It will be a sticky situation.