Hi there! Welcome! I think if it is bothering you, you should talk to someone. They say it takes 21 days to create a habit so the longer you go the more it will become a habit and the more it will bother you. I'm not a doctor or anything, just someone trying to help. I have read about OCD have a family member with it. From what I have read it has to do with control. Our lives feel out of control in one way or another so these become habits or coping skills to deal with our lives.
I think it is really cool that you know how to sign language. I don't think there is anything wrong with it. Many people talk with their hands, gesturing, waving.
I am sure others will be along soon to offer their help. Hang in there!
Dee