Well, your medications could be playing a part. That's a question for your psychiatrist. Certainly if a medication is notorious for decreased sex drive, a psychiatrist can help by making some adjustments.

You don't have to answer, but what is "not as much anymore"? That answer might be a lot of sex to some people. Or not.

In one's mid-30s, sometimes sexual appetites do decrease a bit. Or, even if you feel "stable", it's possible your current sexual appetite when truly stable is less than it used to be. Or could you be very slightly dysthymic? Or sometimes if one goes through a very stressful time in their lives, stuff changes because of the post-stress period. These are just a few guesses. Again, my suggestion would be to discuss the issue with your psychiatrist, therapist and/or gynecologist.

Maybe your bf needs to spice things up a bit, if he's doing the same old stuff as before. Sometimes approaches get old.