I think you should be ok going for a walk and staying away from people as long as you wear gloves for opening and closing doors. Social isolation is tough It’s shocking you can’t get food from a food bank. Here they don’t ask for any kind of proof that you need it. You are over 60 and have no job and no family. What else do they want as proof?

I just checked what our local senior services are currently offering. There are several things. If you need help locating resources in your area you can PM me where you live and I’ll try to find stuff for you. It’s not always official channels, could be random volunteers willing to help.