I would be concerned about the quality of the meter. Next, you need an amperage meter to see what you are running through the breaker. Just replacing the breaker probably isn't very expensive to do if you can do it yourself. But, it would just be a guess.
Shutting off additional loads is easy and cheap. If you have a lot of lights on, it can add load to the converter (and overall system) as well.
I have a 31 foot 5th wheel and 30 amp service as well with 15,000 BTU AC, it (30amps)is marginal at best. Especially with the quick recovery water heater with electric heat turned on.
If I have trouble cooling, I will consider installing a second AC with it's own, separate electrical source.
