It is hard to leave an active business life. I believe that aging is an adjustment for everyone. While he is struggling, could it also be that your life is changing as well due to your aging. You have losses as well as those connected to him which just compound things. It is a normal reaction, and will just take some of adjustments. Learning Uber at 82 may be hard , but he may feel more comfortable with taxis. Additionally perhaps he just wants your presence. I would encourage you to look at a self care plan for your self, self care physically but also mentally, emotionally and spiritually. Start now developing those routines that he can accommodate to you doing so as he ages more it will be less unsettling.
Look to finding respite care, that allows you to have time to be out for a walk, or do things you enjoy. Be in nature. Get your sunshine , develop a new routine for you both. Time after retirement can be an adjustment but also so much fun. Hoping each day greets you with joy