I am developing a big callus on the righ side of my thumb. I am right handed and if I a look at my thumb nail while thumb pointing to the sky I have a callus forming on the right side. Directly on the right side.

 

What is causing this? Should I change the lateral pitch, my current pitch is 3/16 under and 1/16 away from palm so left.

 

Please let me know what I can do?

 

Thanks