I dunno, perhaps changing disciplines to one of the many Western barns out there might be a thought. OP mentions needing to avoid things because she is nursing injuries…maybe waiting until fully healed or switching to a less punishing on the body activity would be a better choice. Western has plenty of challenge to do well…and it’s more affordable across the board. Not cheap , mind you, more affordable.
Maybe trying to see things from the trainers point of view might help in finding the right place as well. Some of these incidents related are clearly wrong choices while others are in more of a grey area. For example, if the barn and their horses are out of your price range, it doesn’t mean they are snobs. It means you can’t afford the product they offer. It’s not personal. They go to Thermal, the AA circuit maybe go to Indoors. All their clients need horses on that level and to participate on that level. That’s their business model. Others serve a different segment of clients, find a barn that matches your current budget. Be honest about that with yourself as well as trainer.
One other thought, were the lessons OP could not perform the exercises private lessons with just OP and the trainer or group lessons? It is challenging for any trainer to structure group lessons to suit where those riders and horses are capable of being successful, if one student openly refuses to try something, it can disrupt the class. Discussing ones physical limitations or need to protect still healing injuries should be an important part,of preparing fir a successful lesson. Trainers can work around limitations or disabilities if they know about them ahead of time.
Trainer doesn’t know clients, especially newer ones, well enough to guess at possible limitations, either financial or physical unless very clearly communicated. Some of these examples don’t sound like there was any clear understanding on some of these limitations.
There’s bad people out there training and communicating via text only with no context of age, budget, physical limitations and realistic goals makes communication and understanding difficult. That said, though, reading these examples has a hint of “woe is me” and the constant in all is OP. Don’t take it personally but sometimes a look in the mirror and some honest self evaluation of ones self can be very helpful. Sometimes such reflection can result in tweaking goals and being willing to change goals to better align with you really have available i in self and circumstances to determine realistic, attainable goals and make them work.
Give that some thought.