My husband doesn't want sex

I had a high risk pregnancy and we couldn't have sex after the 4th month for 5 months we didn't do it for the safety of the baby. The baby is now 5 months and he still doesn't want to have sex. We have done it TWO times since she's been born. I have tried initiating it, I have tried talking to him and I keep getting shut down. I don't think i'm unattractive but I have gained 20lbs since I met him. I don't think it should be a deal breaker, but either it is or he is cheating, which I don't think he is (or hope he isn't) because we have passwords to each other's phones. i'm not very tech savvy but as far as texts go there is nothing there and he doesn't do social media. What else could be the possibility? It hurts to be rejected by your spouse. I feel heartbroken and I don't know what else to do.

I have started to go to the gym, and so far the fee lbs i have lost don't seem to make him any more interested in me.

Edit**

I had talked to him about it in the past and more recently. He himself feels like he doesn't look good since he gained weight. I have told him that it doesn't bother me and I find him sexy all of the time. It wasn't changing though. One day I initiated it, but he denied wanting sex. So I backed up. I tried again a different night and the same thing, then the third time on a different night and when he said no, I walked away mad and he didn't know why I was mad. so I let him know that I hated being turnef down from my husband. We ended up talking and left it at that.

I eventually wrote my feelings in a letter and gave it to him and he has been better about it. No we don't have sex every day or very often but now he is starting to be more hands on me and I'm okay with that. Last night we actually made love for the first time in months! but I have a feeling that my feelings on paper for him to see may have helped. I got him a gym membership, so he can have some time to himself and work on his health and hopefully help him feel a bit better.