Potion sickness results from drinking too many restorative potions without getting some rest. It is very debilitating -- stamina and magic regen are reduced and no beneficial potions will work for you until you sleep. A shrine or even a dedicated Cure Disease potion will alleviate symptoms, right up until you drink another restorative potion. Potion spamming now has a very bad consequence, which is a lot of fun really.

Mechanics
Each time you drink a restorative potion, you get closer to the tipping point. That tipping point is your character's base stamina divided by their level plus a minimum number. The higher your level, the fewer potions you can ingest before becoming sick. The minimum # is the global "a_AUCD", it can be changed to any positive integer you want in the CK or console. In the current version that's 7. If you're updating, it'll be whatever your current game is. Change it to whatever you want by typing "set a_AUCD to #".

Potential Conflicts
Adds an oneffectstart script to the 6 base "alchrestore" potion effects. Resources from SSE Edit view are shown in one of the pics.

Uninstalling
Make the cure at a cookpot using a Wheat and drink it, or change a_AUCD to zero, by typing in console "set a_AUCD to 0", and then sleeping. The alias is cleared, quest unregistered for sleep, and quest stopped. You'll get a popup saying to save and remove mod.

Modding the mod
I've included the text files of the raw scripts in the source folder, SKSE not required to compile (unless you add something that makes it so). The properties of the scripts in their current state can mostly be autofilled. To increase difficulty, you can make the spell an ability instead of a disease. That way shrines and single effect cure disease potions won't work to alleviate symptoms.

Credits
I got the idea from a litrpg story which I thought was The Wandering Inn by Pirateaba (but now I'm not sure). If only they'd have written the damn scripts too I'd probably remember exactly.