My 8 wont start and wont turn over

My 8 decided to stop running today. I was at a store to buy some stuff got in the car to leave started the engine put it in revers backed up about 3 feet and the engine died. I tried to started again engine wont turn at all no click no nothing and then I realized my radio stopped working as well my windows wont go up or down and the only light that I have on the dash is the ambient blue light and the red blinking key. All the other electrics work including headlights, interior lights, fog lights, hazard lights and cigarette plug. I just got back home with a tow truck. Ohh almost forgot the main fuse 120 amp was blown and I replaced it (what a pain in the but) but still it wont start. Anyone any suggestions? Thank you in advance.