All the elements are there, lots of different parts, everything is working as such, lots of skillfully created nuances. You’re surely master in those small details. But despite all that, it still feels that the song is repeating itself all the time. I wonder if you dwell too long in each idea. And for that reason one get’s a feeling that it’s not progressing.
There could be a simple solution to that problem. That transition to guitar part bring into my mind Buddy Holly’s ”Blue Days, Black Nights”. It’s extremely simple song, but it just works. And there’s something for you to take. It’s based on just two short ideas, let’s call them A and B.
”Blue Days, Black Nights” repeats this pattern all through the song
1. idea A (starts with I, ends to V)
2. idea A (starts with I, ends to I)
3. idea B (starts with IV, ends to V)
4. idea A (starts with I, ends to I)
That idea B comes just in perfect place to give the needed movement.
Now you go like this (hopefully I heard correctly)
1. idea A (starts with I, ends to V)
2. idea A (starts with I, ends to I)
3. idea A (starts with I, ends to V)
4. idea A (starts with I, ends to I)
5. idea B (starts with IV, ends to V, the guitar part)
So, we have to wait for the row 5 for the change to come. How about trying similar approach with Buddy Holly. Put the guitar part to the third row and then end the circle with line 4. So, shorter circle with more movement. (It might work, or not. But it's very quick to test with that rendered stereo file. Just cut it to couple of parts and move them around and see what happens.)
Then you have that great part with interesting melody lines/chord progressions starting around 1.12. But you begin it with chord I. So it doesn’t give the change that it has a potential to do. How about starting it boldly with III-chord, or whatever surprising chord (v-minor?), and the find your way back to root.
Sorry for going to details, but I feel that you're about to give a birth to a great song, and I would like to hear it with the full potential of it.