It isn't so much that I *think* about how everything I do is meaningless. The problem is when I *feel* like everything I do is meaningless. It's basically impossible to logic my way out of a neurochemical cascade that's been triggered by something I don't understand.
I woke up feeling empty and worthless. You can tell me my life has value, but I can't feel it. I don't know how to reverse it other than waiting it out. Trying to rationalize away the existential pain only deepens it.