Am I getting dumber or is this normal?

It feels like for the past two years of my life, I have been slowly becoming dumber and dumber. It seems like almost every conversation I have with people is a fail, due to me not being able to say anything. I also have been noticing that I have less and less common sense. And lastly I have been making a lot of grammatical errors that I usually never do while typing, or while pronouncing words. What the hell is wrong with me?!