Idk. I feel like meds should return you to a more balanced mood range, not dull normal human emotions and erase artistic ability. That doesn't sound like wellness to me. Stability perhaps, but feeling numb and uninspired makes it sound like being stabilized at a constant low level depressive state...

I do believe that the extra confidence, frenzy of excess energy and ideas, and reduced need for sleep of hypomania would definitely have a positive effect on one's artistic expression. But I don't think that lacking a hypo mood should annihilate all creativity.

I think wiretwister's suggestion that maybe you need a decreased dosage of meds- this sounds like a reasonable thing to discuss with a pdoc.
I hope your creative spark returns soon. Take care.