The decision is BOTH of yours to make, not just his alone. If you don't want to do it then DON'T.
He may never be there for the baby but make sure you put him on the birth certificate. Make sure that he pays every penny of child support that he owes.
If he theatens you, in any way, file a police report. Don't just take the abuse, you need to protect yourself.
He's not a man, he's a coward. Obviously he was all happy having sex with you and now is not willing to accept responsibility. At 24 he should be looking toward settling down.
Yes it will be hard for you but there are a lot of people that will help you. You will also be eligible for grants in many cases. You can do it!
Lots of women in these forums have regrets, sometimes years later, about having an abortion. There's always that feeling of "what might have been."
You will still find a REAL MAN that will care for you and your baby.
Good luck in your decision.