Hello brainy: Well... I don't know...

I'm 68... & from my perspective... someone who is 76 pretty-much is the person he's going to be... (as is his mother.) You can't change any of this.

So, from my perspective, it's simply a matter of deciding if this mother / son dynamic is something you can live with. If not, my suggestion is... move on...
I see this is your first post here on PC. So... welcome to PsychCentral… from the Skeezyks!

I hope you find the time you spend here to be of benefit.
PsychCentral is a great place to get information as well as support for mental health issues. There are many knowledgeable & caring members here. The more you post, & reply to other members’ posts, the more a part of the community you will become. Plus there are social groups you can join & chat rooms where you’ll be able to connect with other PC members in real time (once your first 5 posts have been reviewed & approved.) Lots of great stuff! So please keep posting!