I think if your dh is normally like this it probably won't help trying to get him to talk about it. I actually didn't talk very much to my dh about how I felt, which wasn't necessarily a good idea... but if I had I don't think he would really have wanted to listen.
My dh is quite typical of many men in that if there is a problem he wants to be able to fix it. So he isn't very good at just listening to a problem that he can't fix. He also seems to have this amazing ability to completely forget things, no matter how traumatic, and never needs or wants to talk about them again. Or if he does he is able to discuss it in quite a matter-of-fact way where I would be a blubbering wreck. I don't think he is heartless or that he keeps it all pent up inside, he just moves on.
You might have to accept that you and your dh are just dealing with this very differently, and it is as difficult for him to listen to you, or talk about it, as it would be for you to just forget it ever happened. (Not sure of course, not knowing your dh, am just going on mine!). If you want to talk, try a good friend, or come on here, or write it all down somewhere, and give your dh a little time. Also your dd is so young, and it is all so new and fresh, and you are probably dealing with sleep deprivation and general shock of parenting. This is probably the one of the hardest times in any couple's relationship, even without a prem baby!
FWIW, I think mine and dh's relationship is stronger now. Like we did this really hard thing, but we did it together, and we got this really wonderful ds out of it that we made together, all by ourselves (well - and a few medical professionals...). Although it probably didn't feel so much like that at the time and I'm sure he has never thought about it like that. Take your time and I'm sure everything will start coming back together.