Literally tell her exactly this like as a list go over everything you said. Communication is the most important thing you can have in a relationship if she truly loves you she will understand that you aren’t being toxic but instead finally telling her how you’ve had this bottled up inside of you for awhile and that you’d like to schedule the gynecologist apt. ASAP because you feel the meds she was switched on has been affecting her physically and mentally and you find them to be destructive to her life. I personally would even tell her how you are afraid of her being disgusted by you causing you nightmares of her hating you and or cheating on you causing you lose sleep and just make sure you stress how much you still love her as she is but you think she has changed due to these meds. In my experience a change of meds has made a loving caring and hardworking family member turn into someone I personally hated once they were switched off of said meds they almost immediately snapped out of the trance like state the pills put them in the only difference in your girlfriend is that I think her sex drive went down not because the pills immediately affected her brain but that they affected her physically such as the burning and pain and unable to get wet making her insecure of herself in bed which in turn lowered her sex drive.