The teacher is so good at listening that it became a delusion that I could speak well
ご質問ありがとうございました。
「先生が聞き上手なので、話し上手になったと錯覚します」は英語で「The teacher is so good at listening that it became a delusion that I could speak well」がいいと思います。
「I was fooled into thinking I was good at talking because the teacher is such a good listener!」でもちゃんと意味伝われます。
「ある素晴らしい先生がとても聞き上手で、そのおかげでこちらが話し上手になったように錯覚してしまう」
「That wonderful teacher is such a good listener that I ended up believing that I was good at speaking」
「実際他の先生だと全然話せなくなってしまうんです。」
「But the truth is I can't talk at all with other teachers」
役に立てば幸いです。