After becoming a werewolf in skyrim, I can't use anything. Why?

I have a better answer and I actually solved the problem for myself. I just encountered this issue as well, plus the beast form ability wasn't showing up in my powers menu.

For me it was a mod issue. The culprit ended up being "Summon were beast (xbox1) by ImperialAgent1992. Once I disabled that mod werewolf form began acting normally even after I transformed into a human and I was able to pull off the vampire lord/werewolf hybrid glitch (which I wasn't able to do when my action button was disabled. In order to diagnose this problem, what I did was deactivate every mod that had anything to do with werewolves whether it affected my character or not. Then see if the glitch still occurs and if it doesn't then reactivate each mod one by one until the glitch occurs again. Then delete that mod. I hope that helps.