HELP! No sex drive normal?

It's been 2 almost 3 months since I had my sweet baby boy and my fiancé and I tried to have sex acouple times - 1. I have no desire to have any sex 2. It's not comfortable anymore and almost hurts sometimes. There was only 1 time where it felt okay and we tried again after that and it went back to hurting. I feel so bad my fiancé is so whorny and it's starting to drive me nuts with the constant touching and trying to be intimate I just don't want any part. I never used to be like this!!