It sounds like this other trainer would be a better fit. Of course talk to your trainer first. But when you approach the other one, maybe you can tell him about your horse shopping and what you are looking for (to be competitive but on more of a push ride), and see how he reacts and if he can help. On the one hand I get them wanting you to learn how to ride the quick catty horses. On the other hand, that is not what you need right now for where you are having had to deal with a difficult horse. You need a confidence booster.
That said, don’t rule out everything with a motor or they takes you to the jump if they are otherwise the right character, meaning not too sensitive, no tantrums. A confidence booster horse can come in many forms. What matters is if you can click with the ride, feel safe, and have fun! I am a hunter rider and I like to go slow. I am the queen of time faults in the jumpers. But when I was last horse shopping, I explained to one trainer that my horse had been off a lot and he also had some dangerous behaviors and I was rusty. So he puts me on this 1.20m packer first even though it’s not a hunter. And while he took me to the jumps and was a more forward ride than I was looking for, if I wanted to compete in the jumpers, I would have bought him in a heartbeat. He was just a solid citizen who liked his job. And I could ask him to wait for the distance in a snaffle …his default was just to hunt at the jumps a bit more. It was a great way to knock the rust off before getting on the green prospects. I wound up finding another very safe and very tolerant horse who is also naturally half asleep most of the time, which is more my speed.