I’d say that your feelings about sex are you your feelings about how you are and about your relationship. It’s not the sex if you used to like it. It’s a symptom for you. Especially after having a baby a lot can change about how you feel.
Your husband needs to back off - and stop sulking. You’ve had his child FFS does he have any idea what a huge thing that is for a body to go through? He should try doing it!
Don’t feel bad. What you need is some respectful, affection at the pace that you can handle. No kisses that turn into a sulk just because it doesn’t lead to sex. You need to know you are safe and secure with your man, which means you need him to have your back while you recover from the birth and from tiredness. Hugs and hand holds, small gestures, with no expectation. Give him it straight!
And then don’t worry about sex. If you liked it once, and your man cares enough to back off, then it will come when you feel OK about everything again and not a moment before.
Also, I’ve had children with two different men. The first one was an asshole about sex after I’d had our child, I felt so tired and he was sulking he wasnt’ getting attention. I went off sex completely. He told me I was probably a lesbian. We split up and I felt that maybe I was rubbish sexually for a long time.
Second man, was really respectful but also really sexy. After I had his child, he made me feel like a goddess. Complimented my body. Affectionate. And crucially gave me affection but never once made me feel under any pressure, he’d just stop immediately if I pushed him away. But he did keep up with making me feel sexy, as in, he’d give me a kiss and say how fantastic it was, and then back off so I wouldn’t feel under pressure. It’s pretty easy to feel sexual when someone makes you feel like that. So we had a really good sex life that was as active at the end as the start.
So, it’s not you.