Need some advice/helpful tips going forwards

[Urtrek]

So me and a friend are playing the game and both are level 74. my mate is a gun witch and i'm Adept.
we are playing the main campaign again in nightmare mode after completing it on insane but we feel we are missing something.

our stats are below 1k atm and I'm also feeling like I'm missing out on really good loot or something but I'm having trouble finding the information about the game.
my question is what should we be doing to get better gear at 74 as we can't beat the second boss atm.
I really appreciate any help anyone can provide.

[76561199750094830]

https://steamcommunity.com/sharedfiles/filedetails/?id=2968079729
i followed this guide with my friend it helped a lot