Suffering succatash! Its ruined, you might as well snap in two 🙂. Alan and kin will be happy though as you have to go and buy another one now.
I never use a clamp unless the record is badly warped in some way. Think about it, you are running a very fine needle in a very tiny grroove with virtually no pressure. The drag coefficient is negligible and in a way you are causing the middle of the record to indent, especially atop a furry/spongy mat. Btw, you can get rubber clamps. Even the little pig from a Revolver is good enough.