cubital tunnel

I am trying to learn how to use the mouse with my left hand. I once took all my notes left handed, for a stuttering class where we heard a theory that left-handed people who were made to write right handed then stuttered. We were testing to see if that would make us stutter...it didn't... but I learned to write legibly, if slowly, with my left hand.
That's not what I am doing here. My right pinky is numb and tingly. My current desk situation is far from ergonomic and I thought I was giving myself carpal tunnel syndrome, with all the work I have been doing. However, that's all the fingers BUT the pinky. What I could have would be called cubital tunnel instead. It maybe left from hitting my funny bone really hard night before last, as it is the same nerve.
So I am mousing with a different hand, so as not to aggravate it, and trying to sleep with my arm straight. That's a hard one, but we will see how it goes.
Maybe I just need a better desk and chair??