lights and air not working

i have a 5-speed 98 cabrio with about 98000 miles that has been very good to me until recently. a month ago it started when i noticed my brake light on eventhough the parking brake was down. the air, head lights, windshield wipers, and rear defrost would not work while the light was on. brake lights, locks, and turn signals worked just fine. this would just randomly cut on and off, kinda of like there's a short somewhere. my boyfriend checked the fuses and they were all ok. two days ago, the cutting on and off stopped and now the brake light stays on with the lights, air, wipers are not coming on at all. i just recently moved and my trusted mechanic is 6 hours away; plus i'm broke. can i fix this problem myself?

I have a 2000 Grand Am SE. The brake light on the dash came on, but the hand brake is down. Should I take it to the dealer or Brake Check?

My wife owned a 2001 cabrio from new. We spent almost 4000 in problems with that car. She had a relay replaced a few times which is what you need to have done. If you start the car and it has the problems you shut it off wait a few seconds restart and it works fine but after awhile it gets worse her car had the relay replaced twice.