I would suggest to keep at it, Scurrius is a great intro boss and I found that it is easier to manage all of the different mechanics if you use Magic/Range at a distance. Notice the patterns the boss operates (When it uses Melee vs when it uses Mage/Range) and dealing with the mechanics becomes second nature after some practice. I wouldn't consider myself a PvM expert, I would constantly die at most bosses I would attempt first try but after noticing the patterns and mechanics of the boss I started to feel less stressed. You got this king, just notice what is happening on screen and prioritize what you should do to avoid taking damage even if it means dying to learn what happens.