sexual attraction

I'm no longer sexually attracted to my boyfriend. I haven't been for a long, long time. We have sex MAYBE once a month. We had sex maybe 10 times in December (my sex drive was weirdly high, I just needed it!) 
I NEVER innnitiate it, and when he does, I have to basically just ignore the fact that it's him.. 
It's so weird because anytime he even kisses me it makes me so extremely uncomfortable, it's like kissing my brother or something. 
Sometimes I will be VERY turned on and we will begin kissing-touching etc., and I will just get so unbelievably turned off that I have to stop, I feel so bad..
I found out I was pregnant a week before I was planning on ending things with him.. I feel so stuck, and like my life is over because I feel like nobody is going to want a young girl with a child.
I also feel so bad for feeling this way, he doesn't deserve it.
I love him, I do, he is my best friend, my provider, my back bone, and he's just all around and AMAZING person...... but we have no spark. And quite frankly I'm bored, and I am sad to say, but I am slowly seeing myself craving other male attention, I never wanted to be this person. 
Advice... please.