How do you deal with the hight heat of propane? I have only cooked with natural gas in the past and now have a propane stove.

I find that it burns very hot and it is difficult to control the heat.

I have it turned down to the minimum, almost flickering out, and have stacked a second trestle iron below the pan and it is still difficult to manage the heat.

What can I do?

The cooktop looks similar, but not exactly like this:
The answer to this might be to get a heat diffuser - this is basically a metal disc with holes in it that moderates the temperature by only letting some of the direct heat pass through. These sometimes come with handles so that you can move them on/off the element while cooking.

google: gas stove heat diffuser for options in your region. In the US I can get them for about $5-10