Car stereo doesnt work.?

I have a rover 25 and brought a new car stereo and fitted it fine. it all worked perfect till i brought a sub and amp. i fitted it and it worked fine till i was goin to screw sub down. like a fool i didnt turn the engine completly off. an next thing i new my head unit went off. i then tried to turn it bk on an it wouldnt work. i then tried my old stereo and that wouldnt work at all aswell.i tried to change fuses under the engine round and nothin changed, i dont no wat to do any ideas would b great
Answer
There should be a fuse panel under your dash, or behind the driver kick plate. check there, as there is usually a 15 amp fuse for the radio in there, as well as the one under the hood