You can't go faster than light because time and space are basically the same thing, and you're always moving through both of them together at a constant rate.
When you stand still, you move only through time, at the top speed of one second per second.
When you start moving through space, your speed doesn't change, only your direction. (You can visualize it as an arrow showing your speed that stays the same length, but rotates in a coordinate system from the time axis towards the perpendicular space axis.) So the faster you move through space, the slower you move through time.
At light speed, you're moving only through space. Your movement through time is zero, so time stops for you.
Going faster through space would mean going back in time, which would break causality.