Hi
Welcome to the MedHelp forum!
One possibility can be pudendal nerve entrapment causing vaginal numbness and inability to enjoy sex. Sciatica and peripheral neuropathies as seen in diabetes or hypothyroidsm too can cause vaginal numbness. It can also be due to injury to the vagina during sex. Low estrogen too can be a cause.
Since I cannot examine you and know other related conditions you may be having, nor is a detailed history possible on net, I have listed the various possibilities that should be looked into. Please consult your PCP for primary examination followed by proper referral. Take care!
Have you seen a DR about this yet? I would think that would be my first step to see if the blood flow to the area is correct. Have you had any trauma to that area which might of caused this?