Wrist pain/injury

I've been dealing with this wrist pain for a few months now—plus there's this slight, almost unnoticeable swelling.
Anyone have a clue what I'm looking at here, or what the move is?

Jack Clark69, you really have to play the game if you want to get ahead

1.) You really ought to be mindful of your ergonomics—how you’re gripping that mouse and your general typing posture—and honestly, just consider how many hours a day you’re actually glued to the screen. It takes a toll on the body more than people care to admit, believe me.
2.) Furthermore, if you start feeling any significant discomfort, try to determine whether this came on out of nowhere following a specific incident or if it’s been a slow, creeping sensation over time; once you have a better handle on that, please, go see a doctor.

I don't spend all day on the computer anyway—plus, I'm right-handed and my left arm is killing me.
As for whatever happened with those events, I haven't a clue—been dealing with this pain for months now.