I would rather study for finals than see my boyfriend.
Why are you choosing studying over seeing your boyfriend?
He is cheating on me with his ex girlfriend.
I'm sorry to hear that your boyfriend is treating you badly. Though it's important to make time for all the important things in your life, you might want to talk to him about what is going on. He isn't worth your time if he can't be faithful to you.
He'll be sorry.
I think you should just end your relationship if this is how you feel. The fact that you do not want to spend time with your partner may be a sign you would rather be with someone else.