Electrical Circuit Not Working After Adding a Light Switch?

I have two breakers for my basement. I put a room in and the lights came on when all others came on so I wanted to put in a switch so l can turn off the light in the room. The light is at the end of the electric flow. To turn off power to room I just turned off the lights hooked up a switch and turned the lights back on. I flipped on the switch, but the breaker tripped. I did not turn the switch off, but threw the breaker back on. The breaker flipped on, but the switch made two fast clicks and all of the lights and outlets don't work now. Hope this makes sense? Any ideas?