Dont blame yourself! Everyone makes mistakes. People told me think of other 3 players as an npc. I still have tankxiety running dungeons so thats why i run it with friends or Trusts NPC (thats what i did throughout the entire endwalker expansion). For alliance raid wise, i was super nervous running as a tank but the more i do it, the more i felt better cus other 2 tanks take over and one boss for each alliance. I have yet to try tanking on the new alliance raid but im still observing other tanks what they do while im a dps. Im not confident tanking it yet youre not alone!