Oh come off it raskova - I think I understand the point you are making, but men are not children. They have a voice that they can use if they want to - if they want their worries to be acknowledged then they need to voice them! If they don't do that (as is definitely the case here) then it's ridiculous to turn around and say "oh poor thing, no-one listens to his worries". The OP has tried talking to him about this a lot, and he is utterly dismissive.
OP - you guys have been together for such an incredibly short space of time, all things considered. I hope this isn't an awkward question, but was this baby planned? That could be impacting on his behaviour. A child is probably the biggest responsibility one could have, and to be having a child with someone you've known for less than a year is a pretty big deal. Of course, people manage after one night stands, but it's not easy, and staying together "for the baby" rarely works.
It is not a good sign that he is not physically interested in you combined with the fact that he is utterly dismissive of your concerns. Crying in front of him about it is probably doing more harm than good as he will just assume that it's hormones.
You guys are young. You should be having an active sex life. If he isn't comfortable actually having p in v sex, then jesus, there are still other things you guys can be doing together to ease sexual frustration!
Whilst I don't think that you should just dump him, I do think you need to try talking to him about this seriously. You are a living breathing woman with sexual needs, and he is your partner. Of course he shouldn't be having sex with you out of obligation, but he needs to listen to what you need and work out a compromise that you are both happy with. It sounds like he is patronising you, which could be an effect of the age difference.
For me personally it sounds like he is worrying about what he is getting himself into, now that you are pregnant, it's suddenly a reality rather than a warm fluffy dream you guys (might have) talked about.
In the long term, you need to make sure that you can look after yourself and your child without him if necessary. This isn't just you - I strongly feel that all women should do this. Even in a perfect marriage a partner can get hit by a bus or die in a car crash leaving their partner on their own to raise a family (this has actually happened to someone I know when she was in her early thirties with two small children).
Knowing that you could go it alone if necessary is hugely empowering. It means that you are with your partner as a choice rather than a necessity.