"Tell him what you want," they urge, "He can't read your mind!" I say it too, of course, but I also often imagine an outcome much like yours: two essentially unsuited people endlessly nagging each other (or one nagging the other, whichever) to do it a little harder, slower, longer, or better. Helpful suggestions are all very well (vital, actually), but if there's no spark, you're not going to ignite one by rubbing two things together until everybody's exhausted and dispirited.
I don't mean to say you should give up right now. You should talk to him sometime when he isn't down there grinding away in whatever dull and vaguely irritating way he's grinding. And don't tell him you need to talk to him about how lousy he is in the sack, either. Raise it as a communication issue, and see how that goes. Then you can give up.
I should caution you, however, against making it his problem that you are experiencing some extremely common, but regrettable, side effects of medication. That is not his fault, any more than being so tragically young is his fault. Both will get better with time.
Andrea Nemerson has spent the last 14 years as a sex educator and an instructor of sex educators. In her previous life she was a prop designer. And she just gave birth to twins, so she's one bad mother of a sex adviser. Visit www.altsexcolumn.com to view her previous columns.