There are MANY medications that can affect one's sex drive, even the lowly birth control pill is a kicker. You may be on the right track.
Hopefully she is willing to talk openly about it--not just with you--but with her doctor. His primary goal at the time was to control her BPD symptoms and it sounds like the therapy is working. But now her life circumstances have changed....she is married. The doc needs to know ASAP that her libido is gone and that the lack of sex drive is having a negative impact on her marriage -- discuss the potential contribution of her Rx. Dr.'s often will not bring up sexual matters in the office unless you do first, and he is thinking "..if it ain't broke, don't fix it." There may be another agent she can take for BPD with less sexual interference or another agent that can be added to her regimen to counter the side affects of the current prescription.
Don't give up...all is not lost! Encourage her to see her doctor about this ASAP. Reassure her of your love and attraction for her. Try to stay patient, but lovingly refuse to sweep the matter under the rug...your love for her is too great! Just the act of acting on the problem will feel better to you. She will thank you one day for your persistence, I will bet on it.
I understand all too well how you feel, my friend. Only in my sitch, I am the wife and the roles in our household are reversed---my husband is the low libido one. Do you know how tough it is to get a man to see a Dr. if there is no blood coming out--LOL! Offer to go with her to the Doctor and check into the medical possibilities first. You may also want to try visiting a sex therapist for additional coaching.
This is a great place to vent your frustrations. The others here completely understand your position and will offer great advice.
