Well, that is one cool hobby. I can understand how learning any new language could be tiring and frustrating at times.

I've gotten to the point in my life where it doesn't take much to tire me out. My mother always warned me that I was doing way too much and someday I'd wish for all that energy back. She was so right! As far as talking goes, yes, I find that to be tiring at times. My husband is almost deaf and refuses to wear his hearing aids. Being the fool that I am, I'm constantly repeating what I've said to him. Dealing with this daily leaves me not wanting to talk at all. And as Silent Void mentioned, I, too, prefer silence.

Good luck with the Mandarin learning and hope this feeling passes.