I totally understand your feelings around toys. For some of us they provide stimulation, but do not function as an actual replacement for certain things.
There are other solutions you will both need to discuss and find together as a couple.
One potential solution could be him considering taking a “drug holiday” (providing he’s stable enough to accommodate) in order to be temporarily free from the side-effects of his medication. Another is inviting a potential 3rd person into your bedroom to provide what your BF can’t, but there will always be risks involved with this sort of activity and it can destroy a relationship if all parties involved aren’t completely honest and open about their feelings.
Chances are if you’re feeling depressed and unfulfilled in the relationship, I imagine your partner also has his own feelings of inadequacy and the only way to ameliorate the situation will be to prioritize communication with each other about what you’re needing or wanting and how you’re feeling.