Ohh, it's such a struggle when your brain just won't chill, right??? I totally get that! For me, I might be wrong but... a warm glass of milk with a tiny bit of honey sometimes helps?? Or, like, chamomile tea, I guess? I know it's not super wierd, but it's teh simple things sometimes, you know?
Also, I heard bananas or almonds are good because of magnesium? Maybe try that if teh others don't work? Good luck getting your energy back for music! You got this!!!