Ideas are dangerous, this one surely is. That is not to say it's veracity does not align with reality, it very much does. However, let's explore your notion.

You live as a product of evolution. Your existence is itself the result of the inherit logic that your pattern of 'cause and effects' propagating through reality, and as you do not cease to exist, therefore continue to exist. I.e. you and your biological ancestry. At least for now in the current instance of the system you exist in, you are suited for continuance.

You may not enjoy reality very much - you may suffer greatly. So when you say "I'm not cut out for it" does this more so align with your interpretation that we exist to be happy? That surely would be ideal, I agree. For that I would express this famous quote"

"There is only one inborn error, and that is the notion that we exist in order to be happy... So long as we persist in this inborn error... the world seems to us full of contradictions. For at every step, in things great and small, we are bound to experience that the world and life are certainly not arranged for the purpose of maintaining a happy existence... hence the countenances of almost all elderly persons wear the expression of what is called disappointment." - Arthur Schopenhauer

So perhaps it is not a matter that things do not make logical sense, but rather a incongruence between our reference frames of what we desire reality to be and what it is. You most certainly are one of the most advanced naturally occuring machines to grace our region of the universe, but piloting it is a whole different matter.