My tank is 445 and I still get pulled for as well…dps are fickle creatures with egos that get bruised easily if you dont pull enough to let them pad numbers.
I was tanking an 8 for a friend trying to gear her toons and she didnt have the best gear so I was pulling consistently, but slower than I normally would in a dungeon of that level so I didnt stress her out and this overly confident DH that was doung the least amount of dmg out of all of us kept pulling everything to make his numbers look better. So me being me, I let him tank it… Took him 5 times to realize I wasnt playing that game with him nor was the healer since he also stood in literally everything and dying too. We were on task to 3 chest it even without him pulling like that and you doing even faster hails little reward except maybe a few points to io scores but at thay level you would replace it anyway. Tanks need thick skins because youll come across dps like this all the time.
For you I would just say: Make sure to use sources for gear priority, rotation and best stats so you can survive. Start out by doing nornal mythics or low keys where the timers are more forgiving too.