Yes I have had trouble with speech/finding the right word, for me it was a period of stress followed by depression. SSRI med helped a lot I'm happy to say - but for a while it was scary. I actually avoided speaking to people for a while except those closest, and was constantly apologising to them for my slip ups. I also made several errors such as getting on the wrong train, my mind was constantly struggling to focus.

Maybe chat to your doctor about it, see what they think. Even if they just reassure you it might be helpful.