Well....
I'll cut to the chase...
You've learned an important lesson...
Unless you r-e-a-l-l-y really really know what you are doing, never use an Event Structure inside a sub-vi.
The Event Structure should be part of the main program, whereas the sub-vi's should be considered liked sub-routines or function calls in text-based languages.
You need to design / architecture the code. You need to understand what it is supposed to do in your mind or on paper. This goes for any programming language. Once you understand how the code should be written, you can proceed to write it.
Having shown us part of the story will may only get you part of the solution. Having seen more of your code, it is more than what you described when I asked "what is your code supposed to do?" or "Can you provide the requirements or assignment description?" Only part of the description was offered.
Reading the tutorials on how to program with LabVIEW is okay to learn about LabVIEW. You need to learn how to design software. Maybe that's the goal of your exercise... I don't know. But you do need to step away, process all of what you've been told and come back with a fresh view of where you need to start. Who knows... You may have to trash your code, refactor it, or if you are lucky salvage some of it. But you need to understand how the flow of the program needs to behave.
21 more posts and we'll hit 100. It's not that bad.. WHen we reach 300 then we'll start to wonder.. 😉
