At this point just disable Ryze until you give him a full rework.
(I know the link is from 5.10, but it serves as a reminder of the impossible task of balancing him.)
He's been hopelessly broken for years now (whether that makes him strong or weak) and based on how unhealthy his kit is there's absolsutely no way to fix that. On paper or in practice it's pretty obvious an actual balancing is impossible.
Your nerfs and buffs make him either a titan that can 100-0 almost any 
without any chance of moving with 
or a Gatling gun 
of spells that don't do any damage.
Give him a 
level rework, and for the love of Ryze mains make the rework more dynamic than 
's.
's Q, or even new champs.
