So, a few things I see that you have set up wrong
1 you use subterfuge mask on the tree while having no energy shield helmet, this is literally a waste of points on the tree, buy a good es helm, itl give you te es and bonus evasion basically the same as your current helm
2 your rings generally suck, get flat damage, preferably cold lightning and Phys but doesn't have to be those exact ones, increased cold damage is very good too ( i recommend one giga ring and a calendars touch)
This will also help with the herald
3 herald procs only when you shatter a frozen enemy, you simply need more cold damage to do this so improving damage will solve your problem
4 I don't see any jewels in your sockets on the tree, what's up with that, losing a TON of DPS there, maybe get a hearth of the well jewel too with gain as cold damage, it should help out a lot