Excess vaginal wetness CAN be a problem, at some point there's no friction and neither partner will feel anything. I had this problem with an ex-GF of mine - she would gush virtually uncontrollably when she got aroused and it started to become a problem after a while. Not all guys are Ron Jeremy and a penis that would be perfectly fine for a normally-lubed woman isn't going to have any effect on an overly-lubed one.
The easiest thing to try is to take an antihistamine before sex, this will dry out mucus membranes and might help with your issue. Also, stop drinking fluids before sex. If you still have a problem, talk to your doctor, freezing or lasering some of the cervical cells _can_ help with this problem, but not everyone reports success or if they do it doesn't necessarily stay permanent.
Good luck!