As to your question, let me ask a question. How old are you? Have you done lots of physical hands on work during your career?
I am in my early 40's and have done lots of physical work with my hands. I started playing with leather about two and a half years ago. I learned very quickly that my hands can't handle tooling. From my wrists to my finger tip I get immediate fits from stamping. Lots of pain. A hobby should be fun, not painful. So, I quit with the tooling.
One more question. Are you casing your leather prior to stamping? And another, are you using veg tan leather?
If you answer no to these two questions, that could be a big part of the problem.