Congratulations on finishing the novel! That cover at looks solid, but the product blub might benefit from some tightening. It feels more aimed at parents, and I'm not sure parents are going to point their kid towards a serialized online novel. Or that a middleschool kid will then read it.
There are still plenty of adults who read YA (I do. Because the market tends to favor style over substance in American YA, that style is usually really strong), but they're going to need something to differentiate the story from the tons they've already read. At middle-school age, a bunch of kids falling into a fantasy world is the coolest thing ever. At twenty or thirty, it's too familiar. Too easy to skim past.
I'd say, take what's weird about your setting, what's distinctive, grab that and write it as a narrative. Write it like you would the first few lines of a story, where you need to make that hook sink in deep. Then follow it with a line or two about your credentials.
The note that it's fantasy written by a philosophy and theology PHD is grabbing for an adult, and the uniqueness of the world should be a good hook for anyone.