you did well to understand what I was trying to say
I'm so glad you could understand me!
you did well to understand what I said!
「よく私の言いたいことわかるね!」= you did well to understand what I was trying to say / I'm so glad you could understand me! / you did well to understand what I said!
「他のいろんな先生に同じ英文で話したけど、私の言いたいことを理解してくれて、一番楽しい会話になったのは先生だけだった!」= I have used the same phrases with other teachers but conversation with you is the most fun because you were able to understand what I said.
「先生はすごすぎる」= you're a really great teacher!
ボキャブラリー
同じ英文 = same phrases
会話 = conversation
一番楽しい = most fun
理解してくれて = understand / able to understand