I Want To Make A Score That Changes When You Click A Button And The Score Shows Up In A GUI

You need to upload the picture somewhere else, (mediafire, a personal website, etc), and then copy the URL. As long as it exists somewhere on the internet, you can link it on MCreator.

That appears correct. It's possible it's reading as holding down the button instead of clicking it once, which would mean that once you click it once, it just continuously goes down every tick. I think this is a bug with MCreator, though I don't recall personally having this problem? Even if this was the case, it should be going up out of control, not down. Are there any other procedures that target your GUI, or the player's variables?

No, what I mean is, have you made any other procedures that have anything to do with the shopping GUI?

Okay, slow down.

Your most pressing problem is that you've made a repeat bracket that repeats infinitely. It's not going to add +1 every 200 ticks; it's going to trigger every tick. Meaning there's a 200 tick delay, and then every tick it adds +1 to the counter. 

To make a variable reset command, you need to add a new 'command' element to your workspace. Make a procedure that sets your clicks variable to zero. Then have your new command element run this procedure. You can also change the variable to player-lifetime, in which case it will reset when the player dies.

If you have a lot of buttons and procedures that manage them, there may be more problems that are affecting this. You may want to consider trying duplicating the element or just making a new, identical interface, step by step, testing it after each step to see if you can find more issues. It's much easier to diagnose problems if you go through them one step at a time, otherwise there's all sorts of things that could be causing the issue.