How do I know what numbers to set for xy on an array for text?

Basically I figured out how to make it so that when you press z on certain coordinates, it heals you a certain amount, the problem is that I can't seem to figure out what value to set the array numbers and I am trying to make it so that when an item is used, it replaces the item with blanks. I got that part figured out but I don't know what values I need to set it so it will work, because if I just say to replace the text when it is at zero, it automatically gets rid of the text without me using the item, and when I try to make it so that when the item is used it sets the value to one, nothing happens and it doesn't replace the text, I know it sounds complicated but I don't know how to describe it. I also found that the array I am using is not the height and width I made it, though I don't know if that is affecting it or not.

the array in this one are the numbers I want to change

This is the image that shows what the item does

and this one I can't figure out what value to set it at so that when the item is used, it replaces the text with blanks.

this is the first set of items that are in the item text sprite and I have labeled which one is which number value on the Item1 instance variable

this is the second set of items

I know that I am making no sense, but I have no idea how to describe this, and for all of you who decide to help, thank you

Too confusing. Why does your condition say if array value = 0 but you only ever set the array value to 1? itemtext.text is not an index of an array. Not really sure what you're trying to achieve but I'm sure it is simpler than this if it is just using an item.