Forces between charged particles, energy is coming from nowhere?

[Lost4468]

So I've created a program in C# with the XNA libraries which is meant to simulate motion between charged particles. I drew a pic to show the problem I'm having and how I'm moving the particle.

 

[Simon Bridge]

You need to show your values and the actual working you used. For instance, the horizontal separation is (1) and (2) are both Δx ... a parameter you give the system. So the only way you get a 2 in there is if you put it there.