The events look like they should work fine, unless there's something on pages 15 and 16 that take priority over the "<Self> Sickness" variable and that's why it isn't running maybe?
Viewing post in How to make plants die if player doesn't water them
Page 15 is the same as page 14 but actives on rainy days (that's the only way I could make it work with my weather system, since a conditional branch was not enough), page 16 is the same as the last page on the template. I think the problem is with pages 6 and 9. Since they only run when the player interacts with them, the common event cannot run the self calculations page (this page can only run when self watered is on). I need a way for the self calculations swtich to turn on when the player has not watered the plants. I tried activating it in the common event, but doesn't work either.