consoleTimer | Simple timer for your terminal | Command Line Interface library

I'm trying to create a program where there are two variables x and y where they continually increment every 2 seconds. 2, 4, 6, 8, etc. I also want a reset button where once pressed, x and y become 0 and 1 respectively.

However the logic problem I'm having is how to get the function return values to be constantly assigned in a changing status to the global variables. I used an array with the name z to hold the x and y values and had x=z[0] and y=z[1], to transfer the multiple return values from the function. Like [a,b].

How do I continually tell the program that each time I increment x and y in my increase() function, that I want x and y to equal the new value? Because the current logic I'm trying to figure out should work once, but instead it doesn't work at all. Instead the values don't continually increase and x and y only increase once from 1 and 2 to 2 and 3 and never more. The reset button doesn't work. I don't know how to transfer the function return values to global values without the values being encapsulated in the function.