It's a tough place to be.
The best way to cure gyno is prevention.
But when someone comes on and doesn't understand what to do and what may happen, it sucks for everyone.
The best thing would have been to be on an AI or at least a serm on his pro hormone cycle.
Next would be to jump on letro asap, and not 2 months down the road.
Now, he has to contend with this.
To the OP:
You can try to adjust your letro and give it more time, but I suggest since your doctor is involved now, try to straighten it out with him.
If not satisfied, and If your own efforts are non-productive, see a another specialist.
Best
T