zvp mid-game unit comp at diamond 3

I've made it into diamond I'm like 3.2k but my winrate against protoss is like 30% I'm probably closer to p1 or even p2 in zvp. I've gotten pretty good at holding 2-base allins that you see a bunch at this level, but pretty much every game I end up with a combination of ling/roach/ravager/hydra and I don't really think it's a viable mid-game composition. I end up with way too much roach/hydra, they get out disrupters/collossi/storm/immortals and my army just melts. When I can get to lurkers with hive upgrades I usually do ok but I can't really get those out until closer to the late game. My roach kiting micro against zealots is decent, I know I want lings to deal with stalkers/immortals, roach/hydra trades ok against archons, but when there start to be disrupters/collossi I really struggle on an appropriate army comp to deal with that. Any thoughts?