BC2001, my suggestion,,,, control the airflow and you will have heat control.
As I just suggested, you should be able to:
1. open things up and get way too much heat, and you should also be able to
2. shut off all airflow and put the fire out. If you can't put the fire out, you need to find out where the air leaks are. Look at intake first.
If you can do those 2 things, you can adjust to any temp that you want.
Do some experimenting with a burn without cooking. You need to find out how to create and control the swings both ways. One burn, a few beers, and you will figure it out.