Okay. First off, aborting your baby is not a solution to your problem. Your baby didn't do anything wrong. YOUR PIECE OF CRAP HUSBAND DID! Besides, killing your unborn child will only cause you more pain and heartbreak than you can ever imagine.
But, a great solution to this problem is called a DIVORCE. If you want to leave him, that is. If not, well, now you have a step-child and a baby mama to deal with for life. Good luck!