"I was diagnosed with Tendonitis in my thumb. I feel like I just keep icing it day and night and splinting it constantly but it’s not getting any better and the pain is sharp and endless. Any suggestions?"
It's important to find a therapist that specializes in hand and upper extremity rehabilitation. The easiest way to know if your physical or occupational therapist specializes in hands is to look for the letters "CHT" after their name, which stands for "Certified Hand Therapist".
In most medical professions, we tend to put different parts of the human condition into neat little boxes. As a hand therapist, early on in my career I tried just to treat hands, wrists and elbows with the occasional shoulder thrown in when warranted.
The problem was, I often times would feel like Bugs Bunny trying to stop leaks in a dam.