I am a pretty casual player, started on the free trial during ShB, go caught up during EW, and this is the first expac I've been around at launch for. I've never done any extremes or savages without unsyncing them for Wondorous tales or my HW relic. I do duty support for my first run of content whenever possible. I absolutely love the difficulty of the MSQ content, expert dungeons, and these raids. if you think you're getting killed out of nowhere, you're probably not looking at the boss's animations or the environment.
And remember: its okay to get hit. its okay to die. you're not doing world-first prog, you're doing regular content in duty finder or with duty support. if you think there's just too much going on at once, do the basics of your rotation and watch the mechanics. once you are comfortable with dodging, then you can work on getting more damage out while things are happening.

you absolutely can clear whatever content you are stuck on. I believe in you.