1993 Nissan Sentra smells like rotten eggs

Hi, Help!! my car is falling apart. For almost a year the brake and battery light comes on a lot, just before it comes on there will be a cracking sound coming from the fuse box, had the alternator checked and its ok. problem 2 - air conditioner keeps blowing fuses. problem 3 - car smells like rotten eggs under hood and inside car VERY BAD, the car has not lost power or shut down, runs just like it use to just real stinky. any help would be much appreciated, thanks so much.