E=mc2?

We all remember E=mc²which we have heard about ever since we started science and learned about last year. But we didn't learn that that's only part of the equation. The whole equation is E²=(mc²)²+(pc)² where P is momentum. If an object is stationary, it has no momentum and therefore we're back to E=mc². Also if an object has no mass(aka light) then E=pc. So the smaller something is mass-wise, then the more like light it acts. Like an electron for example has such a tiny mass it almost acts like light. Velocity is the equal to c*pc/E. You can see that if an object is stationary, then E=mc² and P=0 so v=c*0*c/mc² and v=0. This shows that an object with mass can never get to the speed of light because as long as it has mass, the momentum can never be equal to E but it can get very close so pc/E will get close to 1 but never will reach 1 so v can never equal c, it can only get really really close.