I had this once, you basically just have to kill yourself.
Try /bukkit:kill
It is some kind of potion that gives you basically ultimate health ;-;

 

Milk & Killing yourself.

 

Try flying up really high and then do /gm 0 to make the hearts go down once you hit the ground

 

http://shop.mineverse.com/category/105731
Use the, "clear inventory."
I don't know, it's just an option.

 

Do you still have the item in your inventory?

 

Are your hearts going down by any chance?

 

I'd suggest also leaving the void as it is only crashing your Minecraft.

 

I would suggest trying the following

/help set infinity health

Or resetting your Minecraft.

 

Your username has been listed for the player reset for Creative.
Thanks.