Hi Splendora and welcome,
Your b/f's sexual promiscuity is not uncommon, neither is his reason for doing it. I've found that it doesn't matter whether the abuser was a man or a woman, if the boy child was abused it goes against everything society has taught him about being male (you are the strong one, you are in control, big boys don't cry and a whole host of other crap!) The inability to connect sex and feelings in also not uncommon at all. He was forced to turn off his feelings during the abuse in order to survive it. Unfortunately, the feelings stayed turned off because to do otherwise was just too dangerous.
It's good that he opened up to you and even better that you're taking steps to educate yourself so you can support him.
The books John recommended are the best and there are a host of others in our bookstore. Browse away and come back with any questions or comments you may have. We'll do all we can to help. Just remember, while you can support your b/f, you can't do any of the work for him; he has to be willing to take that step on his own. You can prepare yourself though and learn how to take care of yourself if you're going to stick through this. It's not easy.
If you fall down 10 times, Stand up 11.