That's for you to find out but take a minute to consider, what if it is? You're having fun, learning new things and you're not hurting anyone, so explore your feminine side and enjoy it!
Playing with your sexuality should be something everyone does, just make sure you find the balance. If you stop doing things you should be doing because you can't stop jerking off, then you just need to pull back a little and find a happy medium.
Unlike other addictions, there are no negative side effects to exploring sissification and remember, kinky people tend to be more mentally stable ;)