on the contrary, do not hold your pick like its a Yusof Ishak. Hold it where it has a firm grip but not to the point your FORCING your fingers to grip the thing.
You power chord strumming or downstoke riffing should be all in your wrist. Better still, just use your thumb area of your hand to move it. But maybe your guitar motor level may not be used to just the thumb and pointer finger moving while the rest of your hand stays anchored. The idea is the hand is the fulcrum, and the thumb/pointer or wrist is where you get your movement.
Watch any James Hetfield video, or your favorite downstroke man. Zakk Wylde? Justin Sane?
Attempt anything you want to do slowly. You cant run a 400m race without trying out the 200m first right? Let alone a 50yard dash. So learn your songs slower, or learn guitar skills SLOWLY. chug, chug, chug, chug. Don't need to chugchugchugchugchugchugchugchug now.
Remember, economy of movement. The less you arm move move, the more your getting out of your notes from your fingers.