'Sounds like it is time to move on........' thats crude!
I have a similar problem, yet there is no way i would leave my g/f.
like you, my g/f is embarised of doctors, especialy a gynaecologist.
if someone finds sex painful they tense up, get stressed, get tighter and loose labido completly, and then get even more stressed that things are getting worse. its an evil circle. it must be broken.
I've been dealing with this problem for a while now and we're only just getting results.
you want some tips; we'll dont make it all about you. if she does ever get in the mood, let her enjoy it and dont even bring up sex, make it all about her pleasure not about you getting it in and she may start enjoying it and regain that lost labido. take things slowly.