I think it's great that you're here and that you're learning. But more research (before getting the snake!) would have taught you the differences between thermostats, thermometers, heat guns, etc. The option of feeding frozen/thawed is a well known thing in the snake community as well. Most online care sheets mention frozen/thawed. Months of research would have been greatly beneficial. Since your snake has been on live for the past 2 years it may be hard to switch him over to f/t but certainly worth trying! What will you do if you can't switch him?
Obviously it's in the past so the best thing now is to continue forward. Like I said earlier, I'm glad that you're at least here now. This forum has a wealth of valuable information and insight from many experienced keepers. We all want the very best for your new snake.