I don't have it quite as bad as you, but I have used a
scooter solo at Disney.
I would strongly suggest getting a door stop to hold the resort door open when you are getting your scooter in and out of the room.
If you can afford it do a monorail resort. The buses are no fun with scooters. The drivers will assist to a degree, but it's still hard.
For parks, you can get pretty close to most rides with the scooter, but you still have to walk a little bit. I'd be real careful going on any rides with a drop getting into them like Pirates of Carribean or Test Track. Some of these rides do not have good support to get in and out. The CMs are not suppose to help; because, there's a liability factor. I would alternate shows with rides; so, you get a rest here and there. Enjoy more of the live street entertainment on this trip.
Maybe, even consider early entry, even do extra magic mornings because there are less crowds. Also, you can take a break and rest back at the resort in the afternoon and then get back to the parks for fireworks and such.
Make sure you get fastpasses. I would do all 3 fastpasses early and then try for more.