Mate, you cannot change what is already done. I have known two people that come to mind who have lost one arm. The first one was an Australian lady many years ago - a positive sort! She taught herself to hang the family washing out on the line - from socks to sheets. She developed a technique that was something to witness and I was in awe of her skill.
The other one was a man living locally who opened a shop, fitted it out and filled it with stock. He did very well running the place solo, and seemed to have a huge amount of strength in the remaining arm.
Maybe when things get bad, we need to find and use lots of sheer determination. Giving up can't be an option.