If you can’t get a doctor to prescribe an assistive device (ever heard a doc say they ), you should do research into what types of chairs will fit your needs. I’m guessing an ultralight would be most useful to you. get accurate measurements with help from a friend. I did mine myself, but if you don’t have experience doing self measurement, like for sewing clothes, you might enjoy having a spotter. Save searches on ebay for models and sizes that fit your needs, check second hand stores, charities. check out wheelchair user forums, like on reddit or carecure [dot] net/forum/sci-community-forums/equipment maybe check in on twitter’s disability community, people like crutches ‘n spice, !&&* on wheels. Best of luck. It can be so hard to get help from the medical system.