Too much time without sex, now it hurts!!

So, my baby girl is 2 and a half months old and my husband and I don’t have sex since I was 5 months pregnant. Yes, this much. It’d always hurt when we’d try, so we found other ways to please each other, but now we want to have sex like before and it hurts a lot when he penetrates me! It’s like I was a virgin again, it burns and we have to stop! Even if we use lubricant! I’m so worried, we’re losing intimacy and I don’t know what to do! Any advice?? 😢