Ongoing AC issue with 4th Gen

Hi all, I've had an issue with my AC and blower for the last 3 years. I've so far taken my car to 4 mechanics and have spent $1200. The original problem was the heater wasn't working and the air would only blow on high. I replaced the blower motor and the heater came back but it still only worked on high. Then the blower started only working intermittently. I had some other mechanic look at it and he said the wires had been messed with and he fixed that apparently. The problem continued so I replaced the blower motor resistor. That didn't do anything. The air completely stopped blowing so I replaced the blower motor again per my mechanics advice (this is now 3 years later). He also recharged the Freon. Then air and AC working again. 3 weeks later the AC stops working but the blower is working still. Just blows hot air and there is a weird plastic smell (I'm very sensitive to smell, probably the only one that can smell it). Now my mechanic wants to replace the climate control panel because he believes that's why the air is only blowing on high and the AC isn't working but that seems absurd to me.

I moved so that's why I had to switch mechanics and can't find someone I trust. I have an appointment tomorrow with the Toyota dealership and going to spend another $100 just to get their opinion. Just figured I'd post on here and see if anyone has an idea b/c I'm sick of throwing money away as mechanics just guess at what they think is going on!

Thank you!