Over a long period of time of excessive masturbation, i began to develop anxiety if i tried to stop doing it. how can i get rid of this anxiety?

Excessive? I bet not: How do you decide if this is too much? That may be part of the problem - your belief that you're behaving wrong. Consider the possibility that it's not excessive (it's probably not) and that you just want to have more time for other things. That really may relieve your anxiety. Don't stop altogether whatever you do! It's a perfectly healthy thing for young men (all of us, really) to do.