Facing a problem is one of the first steps to solving it. I'm proud of you.

Can you throw things away, or do you need to just think about "organizing it all" first?

I have a reach extender that helps me when something is out of my reach, or on the floor (though my service dog will pick up anything for me.)

You can begin in one of two rooms, imo, either the one that will show the most difference for what (little bit?) you may do ... or pick the one that will clean up the quickest.

Maybe choose one area, or room for "staging" what you move out of another room.... Make sure you don't just throw things into that area or room, but do so orderly, if you can.

If you can throw real trash away, then go to the area or room you choose, and pick only the trash and toss it into the trash bags. Extra bags and boxes are really "trash" if you're keeping them "just in case" you might need one in the future.

Often when people have trouble sorting through things, whether valuable or not, they begin to think about whatever it is that they are deciding about...bring back memories or worries and fears of not having it etc. Try not to get into actual items right now... just focus on the trash, or items that someone else might consider trash. If you can't throw things out, even trash, then put the trash into trash bags, but don't throw them out yet. That will help you sort through it without feeling any loss.

I hope if not directly addressing any of your issues, that it helps you figure out what you need to do first.