On the Workbench - Exhaustion Levels

Hi all,
So I'm working on a lot of things at the moment but one of the things are new Exhaustion Levels for Dungeons and Dragons.
I can't help but feel that the exhaustion level rules as written and presented in the official books were added at the last minute. They feel like a good idea that was rushed out - or not enough space was given to them.
So I've been working on some of my own and I'd love some feedback:
Point One: Expanding the list to 12 from 6
New Levels
Rules as written i.e. disadvantage on ability checks
Speed reduced by 1/4 of max
Disadvantage on concentration and mental actions (e.g. negotiation/riddle solving etc)
Disadvantage on attack rolls and saving throws
Max hit point level halved
Speed reduced by 1/2 of max
No benefits from short rest
Lose proficiency bonuses
Speed reduced by 3/4 of max
Only move allowed is a Crawl 5 ft. per turn
Speed reduced to zero
Death
Open to all thoughts / comments and suggestions - comment below or use the Contact Us page!
Regards
Stephen
If you would like custom RPG material created just for you then message us via the Contact Us page.
Picture Credits:
Original Image: https://pixabay.com/vectors/cerberus-dog-greece-greek-hades-2027198/
Manipulation: The Grinning Frog team