Bob needs a Bike

I'm on disability and I desperately need some way to exercise, lose weight and improve my condition. I weigh about 380. I can't balance on a regular bike and I'm too heavy for normal 3-wheelers. I want to buy a Heavy-Duty Industrial 3-wheeler and they're rather expensive.
Going to the gym is out. It costs too much and transportation is an issue. Walking too much is bad due to my neuropathy and diabetic feet. I am getting by with very little income and I feel that I've painted myself into a corner.
Yeah, I should have taken action years ago, but morbid obesity can creep up on someone seemimgly before they know it--at least it did on me.
Urgency? Well there's no expiration date but the sooner I can start exercising the better.
If anyone cares to contribute I'd be eternally grateful.

Thank You!