if (StartVoidLoopTime - LastTimeButtonWasPressed >= interval); //if the total time - the start time is greater than 3 sec
That semicolon on the end forms the body of the if statement. A ; by itself is valid code - it is a no-op statement. Therefore, if the condition is true, nothing happens. There being no else statement with this if statement, nothing happens if the condition is not true. The whole point of the if statement - with that semicolon on the end - is what? It achieves nothing.