I presume that you are not on any form of birth control either IUD, implant, depo or pill. Also wonder if you are or were you ever on and antidepressants? Also wonder about how you feel about self-pleasuring and if that works. There has to be an explanation here somewhere. .
That's wise to speak with your doctor about everything you are experiencing; the doctor would be able to advise you better than any of us here. Ask your doctor about Zestra gel; I've never used it, but I've seen it mentioned on a talk show regarding this very topic. Another thing that you might consider, is possibly speaking with a therapist about your stress level, and feeling sad and numb. Having a baby can also put a damper on your sex drive; a lot of women have experienced a lack of interest in sex or lack of drive, due to the hormone changes, added stress of taking care of a baby, and lack of sleep. Although, it may have something to due with emotional disconnect, you'll definitely want to mention that to your doctor.
Another place you may want to post at, is the Womens Health forum here at medhelp ~ there are many helpful ladies there who have great advice to share :)
Good Luck