Character wont stop using skill

I'm not sure if this is the right place to post this, but as of today, my character won't stop using one of its utility skills. At first I thought the key was stuck, so i cleaned my keyboard. The key wasnt sticking anywhere else, for example my internet browser. I even tried to unbind the key binding, and even without any key bound to it, it still uses the skill every time it resets. I went onto a different toon and it wasnt stuck there, just on this specific one. Anybody have any idea how I can fix it/whats wrong with it?

Could you have set it to autocast?

EDIT: If you have there'll be little arrows around the border of it, and none of the other skills.

You make a great point. I didnt even know that it was possible to do that, I just looked that up and toggled it and it stopped. Thanks for helping with my tech illteracy :D

No worries, glad I helped.