I have a similar situation. We've only been married 2.5 yrs and if we ever have sex it is because I ask/beg. I'm at the point that I only ask when I'm ovulating (trying to get pregnant) because his lack of interest when I suggest it really hurts. I generally feel like an unattractive person and having my husband try to seduce me or seem turned on by me would help a lot. Sometimes he even takes Ambien before sex. This makes his performance pretty awful, but it especially bothers me that he feels like he wants to be drugged out while we are intimate.
I feel your pain.