Clarinet

I've been playing a lot of music that is very high recently, up to altissimo A. I noticed after playing this section the inside of my lip hurts because I am biting so hard. I can even see an indent where my teeth were.

Is there anything I can do to relieve this pain. Would moving up a reed strength help, or is a habitual thing I need to fix? My setup RN is either a Vandoren Blue Box 3s or La Voz Medium (jazz) on a Vandoren B45 mp and Vadoren Optimum ligature

Returning to clarinet after playing in school 150 years ago. My teacher assigned me Rose Etude No 1, and I'm finding it very challenging! Particularly the fast runs, my fingers seem to have little minds of their own and the notes are not so even. Anyone have any great tips for tackling it?