What on earth is wrong with me!!!

Y'all, my husband and I have been married less than a year and we've had sex like 20 times total! I feel really awful. I had my son two weeks before we met and at that time I hadn't had sex in 9 months (baby's daddy left the day we found out). We dated 6 weeks (no sex) and then we eloped. I either can't get in the mood or when I am I get sick to my stomach. Has anyone else had this issue? I really wanna have another baby and I love my husband more than anything in the world, but I struggle with anything sexual and feel like a horrible wife because of it.