Changing pick grip after 30 years

Hey there, everybody after all the years 30+of holding the pic between the pad of my thumb on my index fingers I’m trying to hold it more like you guys Troy and also guys like Joe Bonamassa as I could see during soloing my arm tends to move a lot and I don’t have a great pick attack though it works well for rhythm playing I’ll upload a couple videos the problem that I’m having is when I hold it the new way my index finger knuckles really start to hurt and I am not gripping the pic very hard at all no death grip. Also, I noticed it’s very hard to play funk rhythms, James Brown, etc. thank you in advance. Looking forward to learning from all you guys.