Tim,
I had a right side 6x3x3 cm AN removed 19 years ago and had extreme sensitivity on the right side. The left side stayed normal (thank God). The touch on the right side was unpleasant and I had the same reaction to it as autistic kids do: I withdrew. Over the years this has greatly diminished. However, it is not totally gone because I am still ticklish on this side. I decided to get a massage while on vacation a month ago ( first time in my life) and there was quite a difference in perception between my sides. My left side totally enjoyed it while my right one was ticklish. I giggled and arched my back a few times. So, my right side is still autistic for all practical purposes.
The reason you have it reversed, I believe, could be the brainstem issue. The fibers there cross at one point and control the opposite side. So, it is conceivable that either the tumor compressed it and the tissue is returning to normal or the surgeon tapped the area accidentally while removing the tumor. Medical professionals here, correct me if I am wrong. Anyway, time heals and it will get better but unfortunately not right away. Best wishes,
Eve