Welcome to the world of being a guitar player... But don't worry... It gets worse... LOL...
But maybe you are overplayin' yer frettin' hand.... Hmmmmm, you say you been playin' only 2 1/2 years... Yeah, just maybe you don't have to mash down quite as hard to keep the buzz out... I remember when I started playin' a long time ago, I wanted to be sure that every chord change was sharp and so I would overplay the heck outta my fretin' hand...
Rwelated to that think about yer thumb... If you find that it isn't like just sliding 'round free and easy then that is evidence that you are mashin'....
Now, if you find that is the case then yer just going to have to move up menatlly one position toward being a better player and that means.... less mashin'....
But then agin, it might just be arthritis and if so... glucosemin and congointin (sp)...