a couple years ago i spent a good portion of time reading self-help books, reflecting, and trying to find my own why. I ended up writing a personal mission statement for myself that I update at least once a year.
I think for me, my why is to create what I want to see in the world, rather than waiting for someone else to create it. In addition to that, inspiring others to create and adding more representation and diverse media into the world. Sticking to that why can be difficult because the "real" world and the system get in the way (paying rent, for example) but like you said it's still important to keep that in mind.
I think writing out your values and what makes you happy will help you discover what your "why" is :) also, what are you willing to suffer for?