I'm sure you will be able to greatly reduce the scar tissue and strengthen the tissue you have, which should make the area less painful and easier to use. However, since the doctors grafted skin to the area and closed it off - I doubt that you will be able to regenerate the finger. When the finger was first severed, the cells, nerves and other tissue still retained the memory and blue-print for the finger to regenerate - if it had been given the building blocks it needed. Unfortunately, when the doctors cleaned, trimmed and closed off the area, they probably removed any chance of being able to do that.

I'm so sorry - I know this is not what you wanted to hear. What I can tell you is this - the experience you had was for a reason and whatever the reason was will become more clear as you continue to learn and study. This may end up becoming an important tool for teaching others or for helping someone else who finds themself in the same circumstance you were in a year ago.