Why Has My Wrist And Thumb Been Hurting More Frequently?

Why has my wrist and thumb been hurting more frequently? Two years ago I fell on my thumb hyper extending it and fracturing it in the process. Doctors that I have gone to said I have tendonitis in it now and that is why it hurts in the first place though no testing has been done to confirm it. It used to only hurt when I overused it in band and percussion and for some odd reason when it was about to storm. Lately though it has been hurt more and more frequently enough to have begun interrupting my everyday life. I take anti inflammatories prescribed to me regularly and a brace when it acts up. The brace is slightly lower than my wrist and extends up into my thumb so it will support the areas that need supporting. Is it just progressing into a worse form of tendonitis? Am I hurting it more by playing these instruments? What do you think?

-JC