These are my three solutions
1. If your not using cycling gloves, find the THICKEST ones on the market. I just purchased a set of Trek gloves with a heavy gel on the palms.
2. I had a similar problem recently but did not let it get out of hand. I noticed that my body was putting too much pressure on one side and my left hand was taking all the weight. I now move my weight over to my right hand every ten minutes. I don't know if this will work since the damage maybe permanent since the abuse lasted over several years.
3. If all else fails there is STILL hope. The good news is you will be able to ride a bicycle for the rest of your life. You'll just have to sell and road and mountain bike and get a RECUMBENT! Seriously. It may be time to switch rides since what you have is very expensive to fix using surgery. Furthermore, there is not guaranty this procedure will work. There is no cure for what you have and taking powerful drugs to ride a bicycle is NOT the answer.
If I were you, I'd start looking at bents.