publishing a science-fantasy novel!!!!!

hey!!! so!!! i've been working on a science-fantasy novel for the last five years and the first volume should finally be 100% done within a month. it's got me insanely excited!!!!

it's called "megalo sky 1: the knights must rise"! it's about a time-bending teenage swordsman with amnesia who escapes from prison to find his childhood friend, and the cover will probably end up looking something like this:

i've been thinking long and hard whether i'd like to self-publish or try to get a traditional deal, and after a lot of reflection and meditation and pondering i've come to the conclusion that idk. sure, i've researched a ton about all publication methods, but each has so many pros and cons that it's been really hard to get to a definitive decision. i self-published a literary short story collection back in Chile (my home) and it kinda flopped, but i've got the decisive factors (language, marketing, demographic, hook, genre) diagnosed and i think that this second time around could be better. even so, i don't want to throw away my shot (reference intended) at this project that i've worked so hard on.

soooo... i'm in the united kingdom right now (and my story is in english). does anyone know how publishing works here or has any experience? all input is appreciated!! i'm looking for general opinions too, doesn't matter if you know the industry or not. i want to hear y'all's thoughts!!!!!!!