I don't want to stay with my girlfriend if she is unwilling to get an abortion
Why do you have that thought?
I don't want a kid.
It is your gf's choice to get an abortion or not. It's not your body.
She is having an abortion. I'm going to force her to get one.
You cannot force somebody to have an abortion. It is her choice and no doctor will give her one if she doesn't want one. I can understand not wanting kids but you don't carry the kid so abortion is not up to you, it is up to her and you cannot tell her or any other woman what to do with her body.