9 month old nursing every 2 hours

My daughter is almost 9 months old and still nurses every 2 hours around the clock. All day and ALL NIGHT. She doesn’t sleep for more than 2 maybe 3 hours at night and I’m completely exhausted. I don’t know if my breast milk isn’t good enough for her or what. And her dr doesn’t seem worried about it.

Nothing I do or try has helped or worked.

Think I should try formula?

I tried to give her some once before and she hated it but I’m so lost