I'm so sorry to read how bad your pain has become.
I'm not sure if you have CRPS or not but please post over on the
RSD/CRPS Forum
as I know there have been past posts/threads about amputation and considering the nature of such surgery, it would be best if you could investigate every single alternative before making a decision... just my thoughts anyway.
<< edited to add: Sorry, I didn't see that you've just posted there earlier. That's a good place to ask >>