Sorry to hear you've had such a bad injury, I had a serious injury to my right arm last year from which I am still recovering (elbow injuries are tough). I'm right handed, I found I could use Mathematica reasonably well with my left hand using "Sticky Keys" (a Windows features, so I didn't have to hold two keys down simultaneously) and that the function name suggestion features helps a lot, often only the first three or four characters were needed. Of course typing longer comments and the like was slow doing it one handed, I could see speech to text being helpful for this.
