Giving head but I have tmj problems!

hi

I really want to please my husband In bed with head. Ive never been an oral person but I love my husband and he deserves it because he takes such good care of me. But I have tmj! My jaw gets tired or hurts and I cant open wide for him :( any advise ? Im meeting him In a week (gone out of state) and want to surprise him . Getting a Brazilian wax just to be super ready when he wants to enjoy the kitty 😺