Emotional vs. Rational Existential Crisis

Why is it that sometimes the pointlessness of action affects me emotionally while other times the recognition remains purely intellectual? What is it that triggers the 'contagion'? Under what circumstance does my 'faith' (because meaninglessness is a metaphysical question I suppose...) resonate emotionally, and cascade into an existential crisis?

Is it whenever I am chiefly engaged in activities that *feel* meaningless? Perhaps some activities may be meaningless in an objective sense but feel meaningful. It does not have to be art, I feel it even in my day job when I'm in a 'flow state'.

So it seems that what really matters is this emotional engagement with a sense of purpose. It also appears that coming up with a rational reason against the belief of purposelessness of existence does not help me feel any better. I could tell myself "this assertion is a metaphysical one, so really there is no evidence either way." There appears to be an emotional component, dejection, that is independent of the rational one.

Another thought: if the existential crisis is an emotional experience, then is it really one that conceives of purpose? It's just a feeling of "What's the point?" It's a sort of complete and total unwillingness to do anything that smells of delayed gratification, to the extent that I'd rather experience the discomfort of immediate indulgence (e.g. heartburn). Is it a form of self harm? Is it a way of scuttling my own volition?

I had said in a therapy session that I do this sort of thing to enter a state of turpor, one in which I am absolved of responsibility. I put myself out of commission, essentially. That way I have, what in my view is a valid excuse. I can't go out because I'm feeling sick from too much junk food, or because I've made myself sick with a hangover.

Does emotion, or perhaps instinct, operate with a sense of purpose?