You do love him without which you could not have slept with him in the first place before getting pregnant and oyu only feel sorry for him after you discovered much about his family, so dont say you love him because you feel sorry for him, that is not what love is, you love someone for whom that person is and nothing else. its nice you decided to have the baby after the way he is behaving and still support your relationship morally , financially and why not spiritually.
You definitely want to be with him because after all his careless attitute you still support him, what you should do is to talk it out with him, make him realise things will not work between the two of you if he is not focused like a man should be, encourage him to look for a good well paid job or any job after his school and also help you in most of the house work like laundry, vacuum cleaning, cooking, and why not babysitting, after all its his son too. you don't need a baby sitter if he is not working, he should do the working while you are still working because you assist him in all his responsibilities as a man. talk it out with him in a calm and gentle manner, his changes will bring joy and happiness to your life again. you have tolerated too much from him, is high time he knows what he is supposed to do. you are still with him because you love him and he is your son's father, only dialogue between the two of you can change him and bring the life you both shared back in the beginning. but if after some time if he doesn't change in one way or the other, then escort him down the road.
if all girls were understanding like you , there will be no break ups or divorces.