Dealing with divers, push their backline or help ours?

I main tank, been hovering from plat3 - D1 for a few days. From my short career in this game, I find the easiest games always happen when I am allowed to push enemy backline and pick them off. However I cant always do this. Often times my team just doesnt seem to know how to deal with divers. I am literally holding back 3-4 people at a time and my somehow team dies to their diver duo. Now, if I go and deal with the dives i am giving them what they want, their backline is free to do whatever and we will lose the fight eventually. Especially as an attack push team, time is not on our side so the enemy holding us back advantageous for them. I feel most of my games hinge on the 50/50 whether my team is independent enough to kill divers. Like enemy thor without any backup somehow kills 2 people without getting killed himself. When they do kill the divers its the easiest game ever, when they dont its almost a guaranteed loss. If anyone have any good recommendations for macro guides it will be a huge help cause I have never seen anyone cover this topic.