You would do best to call in an electrician.
The lights in the lounge have stopped working because your wiring efforts have disconnected them - with house lighting the power daisy-chains from room to room.
It might be the dimmer that's causing the trip but it could be just one of the individual spots.
You say the trip happens when you switch the lights on and it also happens when you switch the lights off - this seems strange - how do you get them to be on in the first place?
Remember Lord Finchley...
Lord Finchley tried to mend the electric light.
Himself. It struck him dead. And serve him right.
It is the business of the wealthy man.
To give employment to the artisan.
Happy Christmas..., December 2014