Vaginal atrophy but obviously your GP isn't thinking about that!
Have a read of the various threads here, i.e. My Bladder etc., make notes. Ask your Surgery for appropriate treatment, either Vagifem or Ovestin which are used every night for 2 weeks then every 3/4 and 5/6th nights. Some need the former medication nightly.
Do a search for Sylc and Yes products too.