It sounds like multiple instruments are fighting for dominance.
You need to work with "space" between instruments -> use Volume, Eq and L/R balance. Create a working field between layers, so sounds can dance, insted of fighting.
...sometime lead instruments can figth, but it should be intendent.
Anyway, nice "Rough Diamond".
Thanks for "The Budget Cinematic Composer's Guide: LEVEL 0", it had some really nice sources. Thou, I use LMMS (tool) and (VSCO 2) Library (◠‿◠)