Very tight shoulders = caused by fapping?

Simply put, my shoulders are very tight and elevated. I practice Karate a few times a week and my sensei regularly tells me that my shoulders are too tense, sometimes even trying to force them down and then marveling at how stiff they are.

This shoulder stiffness has also been problematic in my other interests, namely drawing, something that requires loose shoulders.

Is it possible that all these years of hunching over a computer screen and tugging my stuff has caused this stiffness, or at the very least aggravated it in some manner?