I completely agree with LaContesse, and everyone else!
She is your baby, you are her mum. It is really early days yet, and while your MIL may seem to have the upper hand right now, that won't always be the case.
Tell your crisis team that MIL and dh are making you feel worse; she because she is an active barrier to you bonding with your baby, and he because he is so unsupportive.
Tell your hv the same.
OK, so you have PND, but you also have an overbearing MIL who has moved in literally and a dh who is unhelpful and unkind and unsympathetic. The pnd will be helped enormously if the other 2 things can be changed. So, she goes home and comes round to help, ie, to clean cook or shop; he needs to grow up, become a man and a father and husband.
None of this is easy, my live, even in the best of circumstances having a new baby is often an utter shock to the system.
You are doing incredibly well despite the awful circumstances. Take your baby, don't give her back. This will be hard, but try to refuse to let MIL take her back next time. Try saying "No, she's my baby and I will deal with her". Practise it in your head. It has been shown in research that imag8n8ng a doing a thing before you actually do it brings about a better and easier action. Imagine doing it.
Take a few days, don't pressure yourself.