Discuss with her regarding this pregnancy. We need to know what she thinks also. Obviously you don't want to live with her. What she thinks. Does she want this baby? Will she throw away the baby in river or dustbin?

If she don't want the pregnancy just go for abortion?
If she want to carry on with this pregnancy, talk to her regarding how to take care of the baby? With who the baby stay? You must share the burden in taking care of this baby as you are the father. you no need to marry but you can give her monthly allowance for taking care of the baby and visit your child every week and be a good father.

By the way, Can your ex-GF sue you for making her pregnant and refusing responsibility? just wondering.

Isn't this called rape. When she is drunk you took opportunity. You are a criminal.