I think you should move barns. It sounds like you have a good option and that you’re just not enjoying working with this current trainer. As a rerider myself, I just don’t do yelling anymore. I wouldn’t put up with anyone yelling at me in any other aspect of my life, why would I put up with it for my hobby, which is supposed to be fun?
If your horse is getting two training rides a week and you’re having one lesson a week, you should be progressing. Yes, there may be occasional days or even weeks where you seem to be going backward, but on a whole things should be getting better. I don’t agree with the idea that your horse needs full time training while you take lessons on a different horse. If you can hack your horse happily and safely, then you can take lessons on your horse.