A lesson is a great idea just in case you have some places to improve your riding, which everyone does.
When I frist started riding really steep runs I felt the same way. Comfortable toe, but not so much switching to heel edge. I was doing what I would guess you are doing, not leaning enough down the hill, causing me to have too much weight on my back foot. The way I fixed it was firstly to recognize that was what I was doing. After that, before the really steep runs, I concentrated on leaning more down the hill, and not putting too much weight on my back foot. After a few runs of thinking about that I no longer did it.