I'm really glad for you the other posters have positive outcomes.
My dd is 15 months and my relationship has suffered hugely and I am totally and utterly resentful of my DH since having a baby. First few weeks he was great, helpful etc, then he stopped and due to starting his own business became a workaholic, totally focussed on that (which is great as it pays the bills as I'm a stay at home mum), but he has done very little with our dd to help, and nothing at all to help me. Before dd he used to cook most nights, was very tidy etc...since the baby and I've become stay at home Mum he never ever cooks, says that he goes to work why should he have to wash up or cook etc as he hasn't got time.
We have not had sex since baby was conceived 2 years ago. We sleep in separate beds now too and we barely talk or even sit in the same room. He says I have been horrible to him. I don't think the men understand what extreme tiredness can do to someone, how grumpy and snappy it can make you.
Body issues wise - My body looks pretty much the same as before so I don't feel too affected by that, although my partner doesn't want sex with me anyway. I still think of sex, just not with him.
It is VERY hard having a baby if you don't communicate (which we don't) through the tiredness and change of roles etc.
You have twins, that is a lot to take on. Hopefully your partner helps you out and is a hands on Dad as well as helps cook sometimes/wash up etc.
As the other posters have said, you will have ups and downs, but it's still early days and once you get to a year, you will be getting more sleep and hopefully you will feel less snappy.
Advice - talk, talk, talk. Don't let the resentment build (as I have done), if things are bothering you, bring them up, if you feel you need more help, ask for it, it's hard for men to understand what having a baby is like both emotionally and physically.
You will come out the other end just fine I'm sure.