I really like this chart. However I would swap number two and number three. I feel like you should lose access to concentration spells pretty early on in stress while having disadvantage on saving throws should come just a little bit later.
1 Disadvantage on Cha/Int/Wis ability check 2 Disadvantage on Wis/Int/Cha saves 3 You cant maintain Concentration 4 You can only take the Disengage, Dodge or Dash action in combat. 5 You are unable to see anything farther than 15 feet away from you. 6 Death
So you start out getting distracted and unable to focus on immediate tasks, with the skill check disadvantage. Then you become unable to focus on anything long term. And then you are so rattled that anything which affects your mental state causes further issues.
Maybe have five apply a short-term mental illness and six provide a long-term mental illness?
Could also add another level above one on this chart and split the skill and ability checks out. That way if you're making a strict ability check, like an intelligence check, you have issues focusing on it right away. But when you make a skill check you're able to use the framework of the information that you have gathered and the training you have received to avoid the disadvantage at stress level 1, then your education framework breaks down at stress level 2 all the way down through the list as currently provided.