The second sentence is incorrect. I'm going to assume you want to write it in the past tense. The correct way to say it would be " you impressed me"

"You impress me" — This implies that you impress me in general. It’s also common to say, “You really impress me.” "You are impressed me" — This is incorrect "You are impressing me" — This is less common but it would imply that you are impressing me in the exact moment that I am saying it.