Went through the same thing, after several years on high rate mobility DLA I was transferred to PIP, lost the mobility award completely due to lying ATOS assessor.
Took 2yrs to get back standard mobility (that one lied as well but not as badly!), another 2yrs and finally back to enhanced mobility last December. I wrote in the renewal application about the previous assessors lying through their teeth!.
Luckily at the time I/we had my Autistic sons savings to help, I bought a used Honda Jazz then got a better deal on a Yeti. Had that for a few months then my credit score finally recovered (after 10 years of my ex-wife’s actions) and I was able to lease another Yeti at a very good price (£200 p/m inc servicing).
Without those savings I/we would have been housebound for God knows how long. Public transport is not an option with severe IBS!! and local taxi firms have very little (apart from a mini bus) that I can physically get into, I’m still not sure how I managed to get into the Jazz but it was fine for a short while!.
Please excuse spelling/typos. Apart from being a clot it turns out I had one on my cerebellum that's now causing various problems!