need some serious help with my coc ice nova assasin

Hey there. I have build up a coc ice nova assasin so far and iam a little frustrated atm. My dmg is good and the speed too but i randomly die to oneshots and i dont know why or what kinde of dmg it was. It goes from 100% hp to 0% in a sec. I just dont know what iam missing on my gear or what iam doing wrong. Can someone pls help me?
I have a pastebin to my pob. Ign: xGeicox if u want to contact me.
thx a lot =)
https://pastebin.com/bwv16XJ3