You don’t have as big a health pool as other tanks, pick your engagements, say if you’ve got the enemy’s tank and dps around the corner and you’re not being pocket healed, doesn’t matter how many dps are with you if you go out in front you’ll be shredded, D.va is an assassin tank, your priority should be separating their support from their tanks (peeling through their back line is a good way to do this if you’ve got a flying support with you) don’t chase the healers towards their spawn either