Have a conversation. If she objects to music etc, remind her you pay rent too, ask her what she would consider a reasonable solution, the same when she irritates you. Of course, start looking for your own place, you are realistic enough to know this is not a long term compatible situation for you.

When she asks why you want to live alone be honest, tell her while she was gone you enjoyed the flow you had, she is a great friend, but your styles as roommates don’t mesh. You want to keep her as a friend.