Abortion is a very personal choice, and I would never advise anybody on whether it is right or wrong. You have two dilemmas here: 1. Do you want to be a mother to this baby? If you do, then that will include co-parenting the baby with your husband, whether you are divorced or not. Being a single mother is one of the toughest jobs in the world. I was one myself.
2. Are you sure that your marriage is over? Alcoholism is a deal-breaker for many people when the alcoholic has no desire to quit drinking. You might consider couples counseling to see if your husband would come around, get treatment and really give your marriage a shot. If you''re sure you want out, then your biggest dilemma is how to handle the pregnancy.
This is one of those life situations that you will have to figure out for yourself what is best for you. What I DO know is that many women feel tremendous guilt after having an abortion and wish they would have kept the baby.
Please think about all the different scenarios of what could happen. Go with what you feel is best for you and for the rest of your life. I wish you the best.