So i'm new to diablo and have started a build I found online (Zodiac WW Barb) and i love it currently able to clear up to a GR70 and can comfortably do T14 rifts but i can't get past those tiers I'm not sure what I need to increase whether that be Damage or Sustain. I can clear a GR70 rift in less than 5 minutes easy if i survive but that's my biggest problem is surviving. If someone could assist me in some way I would appreciate it.
(I don't know if there is a site where I can link you my gear or not)
Survivability after some tiers just becomes an issue - you can improve it by equipping some more defensive choices in cube or in open slots, like Aquila Cuirass or Ancient Parthan Defenders and so on - but later on in the game you will eventually be squishy, on any class, especially once you go above GR 100+.
I haven't played barb myself in a while, but if you play on PC you can link your profile by going to diablo3.com and logging in. I don't think such an option exists on console.