sex help

Alright ladies, I need help. My SO ALWAYS wants sex. Every morning, every night, whenever he thinks about it. Which is a lot. It used to be fun until I got pregnant. During that time I was so exhausted and it was painful so I really just wasn't interested. I still had sex with him because he wanted to and I wanted to keep him happy. Then we had our son. And sex has been better, it doesn't hurt with the exception of one position. But unless he says something about having sex I don't really have any desire to. And I don't know why. It's not like I don't enjoy it because believe me, it's phenomenal. But I just don't have the desire until we've already started. I feel like part of it is because there's just no foreplay anymore. He just asks, so I lube up and bam. There's no 'here let me touch you there', or anything like that anymore. And I know the other pet is just something wrong with me. I looked up a sex therapist in our area but we don't really have extra money like that so I just don't know what to do.