Do you think that I should leave my bipolar girlfriend to cry herself to sleep?
Why would you not support your girlfriend when she is obviously in an emotional state?
I'm tired of her constantly crying over the most stupidest things.
She is your girlfriend so you are supposed to support and comfort her whenever she is down and out. That's your job as the boyfriend. Abandoning her when she needs you most will just hurt and confuse her.
I think she just wants to ruin my life and my future.
If that is how you feel then it might be the best for both of you if the relationship ends. It isn't healthy for either of you if you don't want to take care of her when she's in a bad state.