Chaotic thinking

It is quite funny. Seems like in so many years of language learning, I haven't realized what exactly the words I'm speaking mean. But the more I do to my thesis, the more readings I do, the more uncertain I am about the expressions I use in my speech. Do they really mean what I mean? Are they accurate enough to make myself clear? Can others understand me? Can others get the exact information that I'm delivering? These questions have been part of my habits. OMG! Professional illness?