A lot of people think RV living is cheap because there is no mortgage/rent, electric bill, heating, etc..... However, you have to keep a gas tank filled, usually on a vehicle getting 8-10 mpg that also burns oil. A 100 mile trip may cost you $25-35 depending on mileage and gas prices that day. Start doing those exponential increments. 1000 miles will cost you $250-350. Plus oil. Expect mechanical issues that will not be cheap. Heating can become an issue depending on where in the USA Carmen Sandiego is, so there may be times a $30 per night campground with shore power is your only option other than hypothermia.
Many of those people you see in those Bob Wells videos that brag about living in their car on their small SS check share your financial woes. It is a sad state that our country keeps people alive longer yet doesn't do more for them. However, all the angst in the world is not a solution to that. There comes with that car dwelling thing a philosophical question of whether that kind of life is actually living or just existing. One particular woman he interviewed was in some tiny little car, ate every meal on gas station sandwiches, and her days were pretty much sitting in a chair staring straight ahead because she had to conserve her gas so much she didn't dare to run that engine any time other than when she moved. In my humble opinion, she is existing, not living.
Another went on and on about "freedom" and "independence" of not being tied to a mortgage or lease. Further in her interview she mentioned that she goes from child to child to child and lives in their driveway for 2-3 months at a time, plugged into their electricity, eating their food... What is free and independent about that? That is the definition of co-dependency. That is being a burden. However, often it is a product of circumstances. The reason I brought that up is that Bob goes to great lengths to sell that fallacy of "freedom", and people eventually buy into the brainwash. If you follow any of those RV Nomads that have youtube channels, they live on donations. Charity. Internet e-begging. Again, it is only my opinion, but I am not going to live in a world where I have to beg people for money, for solar panels, batteries, drones, gas money..... Generally one step above how animals live, JUST to brag about not having a job. Many of them shower once a week or less. (You can tell because they wear hats to cover their dirty hair.)
And somehow, most have money to smoke and drink. Some brag about always having their baggie of weed. It would seem when you are close to penniless that the vices should be the first thing to go.
So try very hard to leave behind any romantic notion about living on the road as a nomad. It is a very difficult life in the best case scenario. Add to that limited income, diminished physical ability and a general lack of familiarity with that kind of lifestyle and that is something you need to REALLY consider carefully. If you DO go down this road, a lot of people here will be pulling for you, Including me. It's a gutsy move. Thus far you have done it right, asking a lot of questions and drawing on experiences of many people with varying levels of experience.
