I was hesitant to reply to this subject because I'm new to diabetes and have limited knowledge about it.
However my mother-in-law had her leg amputated when she was 55 and it is very difficult for both the patient and also family members. The emotional stress is something that I find hard to describe. She also had phantom pains in her foot that was no longer there. I'm sure you will both go through some very difficult times , but always try to give him your support and love. I wish I could've done more but that's no longer possible.
When I get to the end of my rope , I tie a knot and hang on.