HELP!!! Electronic things hate me!!

Alright, i was putting a mono amp on my rear speakers and there was only one frequency playing. My friend Andrew was helping me and when i suggested putting the amp to the side coming from the deck, he agreed and we hooked it up. We started the radio and turned on the amp, all of a sudden the fireworks started. The two 15 amp fuses blew on the amp....WEEEEEE! Then we disconnected the RCA cable, the REM wire and took the amp out of the car. The speakers were all hooked up again and when i tried to play the music.....nothin! The LCD screen still plays and the volume goes up, but no music. We had the deck turned to the rear channel and it is a 4 channel deck. It is a $675 deck w/ an LCD screen and don't want to blow it, but want to know...did I??? Someone please help!!