A B+ in an AP class is great! Wouldn’t you already be enrolled in the AP class or are you planning for next year?
I wouldn’t let fear of getting a B stop me but I would consider your workload. In my
AP Lit class I’m currently annotating 3 novels at once, while I’m also memorizing lines for the play, finishing submitting college apps, and it’s football season (I’m a cheerleader). I probably bit off more than I can chew. Who needs sleep anyways?