Fellow non-trad arts major here. No science background either.
I don't think the tier of school matters -- the 'problem' is that you are probably a highly intelligent person and accustomed to learning things like an artist. In comparison, M1/M2 are pretty much a cakewalk. I remember a conducting final where we had to prepare an opera act (about an hr., 150-200 pages of music) and conduct all of it from memory ( you conducted the prof who was playing the whole score on the piano and poorly singing all the lines) during which time the professor would stop randomly and ask detailed questions about that moment in the score (who's playing? who's singing? what word are they singing? what does it mean? What's happening on stage? What's about to happen? dynamic markings? meter? which important cues are coming? etc). Compared to that, memorizing some PPT slides for biochem is nothing! I suspect you had similar experiences in your undergrad as well.
The other issue is that you're just at the beginning -- the simple scales for instruments, simple vocalises for singers, theatre games for actors. Just like you did with your art, focus on mastering the fundamentals and allow things to build at their natural pace. Supplement as needed with outside materials. Talk with your faculty and ask when things you see in BRS will be covered in your curriculum. I know ours skipped around a good bit and it looked like we weren't covering something but then we'd get to it later in the year. Either way, the material will build on itself and you'll get to where you need to be. Maybe talk to some smarter upperclassmen to see how they felt and if it might get better/tougher going forward.
(I realize I may just be responding to a troll post, but thought I'd give him the benefit of the doubt)