Everytime I think about this, I end up with "the fact that something is not in the state it desires to be in seems sufficient and necessary".
Maybe electrochemical imbalance is what's experienced as consciousness, all the way down to the smallest particles (or even beyond) - then, organic consciousness would just be an immense abstraction of the same thing that drives physics itself.
I feel like this is satisfying, but then again, I'm not Joscha Bach :-)
It's axiomatic. The universe exists because feeling exists. Physical matter is subjective experience. More complex matter up to and including the human brain represents more complex states of subjective experience. The processes in the brain feel like something because a process is a thing.
that particular atom exists because it feels like something to be that particular atom
seems to beg the question somewhat - where is "feeling like something" coming from?