tanks and 7.9

so when i saw the patch notes for 7,9 i really thought tank would finally be tanks you know not just get melted like im a sona or something but... after now playing a bunch of games with my usuall sion malphite galio naut what the hell is going on like i've never in my life felt this level of just squishy like i feel like i'm playing a sona top like my hp bar keeps melting no matter how tanky i get and i don't get it like my last game now i played sion top and i became 4/0 i was doing well was going full tank cause my team needed it and yet..... i still my hp keept melting in every fight we got into for some reaon and i just... don't get in same with laning just my hp bar keep melting and i don't understand it cause im not doing anything wrong and the enemy laner is only like auto attacking me like 3-4 times and throwing a spell or 2 and my hp is just randomly gone... like whats going on i don't get it...?