Bathroom fan won't turn on
OK, it looks like you wired the fan in series with the lights. Disconnect the fan. Get the lights to works like they did before. Then, after turning off the power, disconnect the two wires leading to the lights. Connect the wires from the fan to the wires from the lights, white to white, and black to black if in the USA. Then connect those two sets to the two wires that originally fed just the lights.