Hi, welcome to the forum.
First of all; glad you shared your progress. Now if I become too annoying by pointing your mistakes, sorry for that. You don’t have to optimize everything to have fun with the game but I’m gonna suggest those anyway so you can check, learn and choose to use or not by your free will.
Big question: What exactly you want to focus on? Using Shadow Strike? or Melee hitting? Because you don’t do neither of them efficiently right now.
The set you’re using is a melee set and mostly supports the WPS(Amarasta’s Quick Cuts etc) but the class combination you have no Auto-Attack skill so you gonna create one instead of using basic attacks. You can use this component which provides an Default-Attack Replacer https://www.grimtools.com/db/items/2888.
Or you can change the gear and focus on Shadow Strike which is more reasonable with the class combination you have because Star Pact have cooldown reduction bonus and it let you use Shadow Strike more often.
These are examples of Shadow Strike focused Spellbreakers with SR set and Morgoneth set but it can be done without them with ease.
If you let me know which one you wanna focus, we can help you through that way.
But the general problem with your build beside not focusing anything in particular;
You are using a pierce damage amulet yet you’re a cold damage build; a easy and good replacement for it is https://www.grimtools.com/db/items/7828 this.
You have focused your -%X Resistance Reduce debuffs like Night’s Chill and Rumor devotion(which is good) but there are 3 RR debuff type in this game and the other 2 can stack with the first one. You can get one by taking ‘‘Hand of Ultos’’ or ‘‘Viper’’ devotions and other by ‘‘Revenant’’, ‘‘Rhowan’s Crown’’, ‘‘Manticore’’, ‘‘Scales of Ulcama’’. Actual Resist Reduction formula check this to understand how RR works and stack together.
You are also not using the skill ‘‘Amarasta’s Blade Burst’’ and it’s buff node ‘‘Lethal assault’’ that will provide a good amount of damage to your all attacks during it’s time.
You have some other devotion, gear, component and augment problems but we can check those after your reply.
Also check the official game guide’s combat part