1. My English ability was poor, and I *was* impatient with not being able to express what I wanted to say.
2. Although I have things I want *to* tell you, I cannot express my *thoughts* in English well. {We don't really say "express my mind" but rather "express my thoughts". There is also "speak my mind" to say that you give your opinions openly and honestly, even if it is not pleasant.}