Yep, first couple of years I had a bad habit of gripping too hard.
Opportunity is often missed because it wears suspenders and looks like hard work.
I have arthritis in my fingers, which adds a bit of frustration. But, I found I can brace the note playing finger against the nearest finger to it, and it doesn't hurt so bad. I'm working on Kamarouski #2 and it's almost up to speed. Song really got stuck in my head. I was humming loudly on a motorcycle ride and my husband pulled over, thinking something was wrong with the bike. Nope just me and Kamarouski. I am not a singer!
I have been playing for many years and I still get cramps in my left hand every so often. It's usually the result of gripping the violin too hard while trying to position your fingers, When it happens I stop playing for a few minutes and then when I start playing again I focus on relaxing my grip on the neck of the violin. It also tends to happen more when i don't play for a few days. If I play regularly it tends not to happen.