When I had a work computer that was solely mine, I used to mouse left-handed. It was really, really nice. Comfortable. I did this at home as well when I was using a desktop...and one with a different setup.

I'm like wiliqueen in that I use the mouse as little as possible--even less than she does--and rely heavily on keyboard shortcuts.

I suspect that, as someone as entirely left-handed as you are, that your right shoulder and back muscles aren't as strong and limber, and don't have the endurance of your left ones, and so are even less disposed to reaching repeatedly over the keypad like that.

*sympathies* I hope you find a better solution quickly.