Very new player, started playing a few weeks ago.

I got super lucky and found a Divination Card that sold for 40 divine and was wondering how I was doing on my build.

I've been following the Maxroll TR Ballista build and I still see very squishy. I think the issue is that I am not really understanding the mechanics or the minor details behind the build and if someone could potentially provide some insight or maybe where I am going wrong? I've read the guide 1000 times, watched probably 100 videos but something still feels off.

PoB: https://pobb.in/KhwacHfLH7ej

Side Note: I also got a bow that seems like it has an awesome crucible tree, but I am not sure how to get it to show stats in a screen shot.