Clearly you are confusing the concepts of time and space. When you return to the starting point you have gone back in SPACE.
Moving from room to room is not necessary for you to move forward in time. Sitting in a comfy chair immobile is also an example of moving forward in time.
When your boss asks you to show up at 8:00am for work, do you manage to do so? If you wish to watch America's Got Talent on the television at 9:00pm, can you do so?
I don't mean to make light of your beliefs, but how can you doubt time while simultaneously using it every day?
I believe you are over thinking the concept of time. It is a measurement, just as length, width and height are measurements.