So much to say, but not really

"I'm tired"
Has become my signature phrase. I say it when I actually feel tired, when I'm mad even when I'm happy. It mostly comes out when I don't know what to say. I've said it so much that I don't even realize it escapes my mouth. The default phrase when there's nothing left to say. I constantly look for another phrase to use, something that can encompass all of my emotions in one. But I haven't found it and the clock is ticking when someone asks me, "How are you?" What's the word? How do I feel?
Forget it.
"I'm tired."