eatenbyagrue said:
It's a standard mouse (2 buttons + wheel), and I don't want to spend money on one of those gaming mice
Oh, but you absolutely should.
Even in normal circumstances, a few extra buttons can be enormously useful. You can remap a lot of things to thumb buttons. Also, even if your thumb and index finger's out of commission, you've still got three fingers on your left hand. That's enough to use WASD. Though because your little finger being shorter than the others, you might have to remap some keys for comfort. Then you could map the usual keys (Q, E, R, F, C, Ctrl, Space, etc.) to your mouse's thumb buttons, if you had one. With practice, you could play Keyboard + Mouse games unhindered.
When I broke my left hand, I still played games with a gamepad. Had it on my lap and controlled both sticks with my right hand. It was tricky, and I couldn't play fast-paced games well, but it worked out alright. Final Fantasy X was the game that I played the most, because it didn't require too much dexterity.
Whenever there's an obstacle, ignore it and proceed anyway. Just make shit up as you go.