3 track light bars, 120V 20A. Originally, there were 2 lights wired to one 600W Single Pole dimmer, and a jumper to a separate box with another 600w Single Pole dimmer in it that controlled the other light. I will be eliminating one of the lights and junctioning the connection in the attic.

The wires in one box are as follows: 3 wire (Red, Black and white plus ground) and a 2 wire (Black, white and ground)
When I took the original switch out, the red wire from the 3 wire and the black wire from the 2 wire was connected to the switch. When I turn the power off, the bathroom and bedroom also turn off. There is 3 way switch in the bedroom/bathroom and I assume this is where the 3 wire comes into play in the dimmer. When I installed the new switch, black and red plus ground, I turned the power back on and the power bypassed the switch and the lights were on. What did I do wrong?

Do I need a 3 way dimmer because there is a 3 way switch within the circuit?

I just realized something..As I mentioned, there are 3 tracks, one of which was connected directly to one single pole 600w dimmer, and there was a jumper to another box that lit the other 2 lights. I took out the latter switch and wiring as my plan was to eliminate one light and consolidate, keeping 2 lights into one dimmer. BUT... since I disconnected the jumped wire which I believe kills both the light I plan on removing, PLUS the one I plan to keep. So, I need to bring power back to the one light I want to keep and connect it to the dimmer. Am I best to go into the attic and splice the wires going into the currently live light? (after shutting off power, of course)

Still I think this shouldn't affect my switch problem though, but adds to my aggro. Any suggestions is greatly appreciated!