help me fix my build

Hi, first time poster
I am stuck on tier 15/16 bosses and sometimes maps..
i get one hit and not sure what could help

I have never come this far in the game before normally play on hardcore and die before maps :P this time I wanted to see what comes after map.

could someone help me out?

I only have 20C so can't really buy items.

my build:
https://pastebin.com/6F5K233w

Thanks