Hi, Andy.
I understand the draw to this, especially when we have no money, little health to be around others, and the mobility is appealing. Not to discourage you, here's some more things to consider.
My friends live in a trailer on the streets. She has ME/CFS, can't afford rentals here and needs money for medical. He has health problems too, can't work much and doesn't want to go on disability.
It's hard. They have to move between certain hours every night because people living in vehicles aren't allowed to be parked I believe between 2 am- 6 am. Also, if it breaks down and needs to be in the shop or someone needs to fix it, they can't always stay in it. They also have had problems with leaks and mold. You'll need to watch out for formaldehyde and I don't know what else, it was a big problem with the FEMA trailers people lived in after the hurricane in Louisiana. The formaldehyde made people very sick.
My friends have a bike they ride to places close and an extra vehicle because the gas cost a lot to drive their home on wheels, and they want to be inconspicuous as possible, too, to prevent break ins and more. For some reason, I could be wrong, I don't think it's legal to live in your vehicle here.
I think the best situation, if you wanted to have one, is to be able to live in it in someones back yard and to have use of their house. That's tricky, too. I don't think it's legal to do this either, have to be stealth about it and have neighbors that wouldn't mind.
There's lots of people that do live in vehicles. It's done. In one town by me, some park by the beach, bbq and have tables out where they play games. These are healthy people though.
I know in the desert there's an area where people live in their vehicles and can do so legally for free for many months of the year. Then other months I think there's a fee. A lady I knew, her significant other musician lived out there. It's hard. Nearest town was many miles away and she said a lot of the people who live there, not sure now how she said it or how to word it, they were problem people.
Sorry, hope I'm not discouraging you. Just some things to keep in mind as well as what others wrote. Some of what I wrote may not be the case in other areas, so it might be easier in those regards. I hope you find something that works well for you so you can rest and get the help you need.