lol i have had the same problem with pain. i used my mx 518 for 7 years, esl gaming, rts, ego shooters. role play games ... and if happened from one day to another. after i have started to play more league of legends
first you should buy these powerballs^^ it will help the first time. (helped me a powerball costs 5$)
a trackball wont be false for only browsing, watching movies or surfing the internet. (for relaxing your stressed hand 20$)
i was forced to buy a bigger mouse. i bought a roccat kone+ never had pain again. but you should try some mice, every hand is different.
dont go for smaller mice^^ the pain comes from an unrelaxed positioning and palm resting on the mousepad and your mouse dont sustain your hand correctly -
while you re holding your mouse your side of the hand is going more in, thats the pain in your palm comes from. a more plain position and your hands hurt less, but you cant use a mouse
.
your wrist will stop hurting if your hand is more sustained by the mouse. i think your hand grown a bit and your mx is to small right now, that was my problem. so i went for a bigger mouse and the pain dissapeared.
and if its urgent buy some "Cold Care, Kühlgel, Pferdesalbe" because your hand is stressed.
less gaming for some time buddy^^ i would strongly recommend^^
and if you dont game^^ buy a trackman trackball and you wont have problems anymore
your hand should be in a more plain position more resting on a mouse than holding her and you shouldnt make a claw this happens if the mouse is to small.