uhh... yeah, i see what you mean. the beginning and the first few chapters are great, but then it gets weird. and not good weird. the theme is chaotic so its reasonable at parts, salvageable in others but some scenes and dialogues needs to be redesigned. i am on the chapter 7 right now, haven't read it to the end but those are what i spotted so far.
i can't pinpoint where exactly but i think you got disconnected from the story somewhere in the middle. it is either that or it wasn't that thought about. the first several chapters were very immersive but the middle feels more like you were just checking a list of events. that or you envisioned the first and the end part as i see that you rebounded in the later but couldn't find the right way to tie them together. if the tie is the problem, don't try to continue. just stop. read what you had written. think about what should come next. what feels right. write it and read again from start to see if they fit. if it is disconnection then wait. write something shorter. listen to a music you like. read what you had written again. see if you can reconnect and continue in a way that is satisfactory. write when you feel ready because when you force it, what comes out is mediocre at best.