Generally Sunqua peak is the hardest fractal on the first try and becomes one of the easiest once you get used to it, Because everything boss does is aoe mechanics and it is always the same order everytime (tho it may change depending or the dps boss may skip some phases if you dps it too fast etc) sometimes people do it without even getting damaged in t4 because boss becomes so predictable but it is fair for new players to struggle , i had the same issues when i did it for the first time, you'll start to play from muscle memory after the 3rd or 4th kill so keep trying