I'm very sorry you've had such a difficult few years, a lot to deal with and losses to bear. I hope you continue to have support from family and friends, which of course is vital for keeping your spirits/mental health up.
I've had my own challenges in the last year or two and would just say how humans seem to adjust and adapt to changes...in time, as the months go on. In the meantime it is painful and difficult isn't it. I had to keep the faith that life would change... it never stays the same.
Distraction is good. If you can develop a fresh interest or past time, learning about something new which captures your enthusiasm it can help. Things you can do at home. So many things in life to do. Ideas can come unexpectedly, to spark our interest...from the internet, books, magazines, TV, over hearing a conversation.
For myself [and for example], I found a new interest in cooking, trying new recipes, redesigned a part of my garden, connected with an old friend via Facebook messaging, discovered a wonderful new coffee shop, started knitting again for charity and am studying philosophy online. Been kept busy, the months have passed and I feel a lot better. I'm 76 too.
I wish you the best, and I hope you can find ways and something to compensate for the way your life has changed, and can eventually come to terms with your limitations. You have been very brave.