Chieftain fire smash build - is there no hope for redemption?

Here is my build: https://pobb.in/oqj_YB_kiC2-

This is the first time I've completed a campaign and transitioned into the end game. This is my first maps build. I didn't use any guides. I did try to follow the rule of 300-400 hp per act. My objective was to craft a fire-mace-smash build following the recent melee rework.

So far, I've managed up to tier 7 maps, which I can usually handle if they are magic-tier (or blue). However, I struggle a lot with rare maps (yellow color). While I can complete them, my character often dies multiple times, and sometimes rare/yellow tier 7 feels nearly impossible. My high latency of 150-200 ping, due to no nearby servers, certainly doesn't help.

Is there any hope for redemption for this build? Or is this bricked and I need to start over? I love the feel of the build. Is there a way to fix it?

Edited: Tweaked build slightly based on suggestion

You have sunder and earth shatter, the first with a 4 link the other with a 3 link. You are supposed to have a 5 or even a 6 link by the time you reach yellow maps. Using both pride and phys added as fire is also bad because pride isn't scaling the fire damage you get. I didn't look at your passive tree but it's likely suboptimal as well. The build is probably salvageable but you really should take a look at other builds. Not to copy them but to try and understand what kind of gear you should have and how to scale your damage. You are way off at the moment.

Thanks. Do you have any good fire melee build suggestions? Sorry I am a complete noob to the scene and don't even know how to tell if an online build is good or bad?

I tweaked my setup slightly based on your suggestions. Key issue seems to be that I keep insta-dieing in some maps, but generally, I have little to no difficulty in killing regular mobs fast. For example, I was doing the unique map with fairgraves - and I couldn't kill him. He kept 1 shotting me with his skills.

I increased chaos resist but I am still at -20% because its nodes are pretty far on the tree, and I still don't have the craft recipe for it.

I tried getting a 5/6 links - wasted around 150 orbs of fusings and couldn't get it done. Do I just have to farm these in thousands to be able to do this?