This loop after a certain amount of time behavior is best implemented with a SetTimer function invoking a Subroutine.
Additionally, since your script holds down the Shift key, you would need to also have the hotkey be invoked whenever Shift+Home is pressed as well, so that it can be turned off.
Final Code:
Home::
+Home:: ;Alternative hotkey definition that invokes on Shift+Home
KeyDown := !KeyDown
if (KeyDown){
SendInput {Shift down}
gosub, clickSubroutine ;To trigger the first click immediately
SetTimer, clickSubroutine, 1000 ;To trigger clicks after every 1000 ms (1 second)
}
else{
SendInput {Shift up}
SetTimer, clickSubroutine, Off ;Turn off the clickSubroutine Loop
}
Return
clickSubroutine:
Click
return