Sounds like the problem is your switch in the steering column. I'm starting to have the same problem (no low beams, only the high beams for headlights) and my left turn signal is starting to spazz out. I know for a fact my switch is going. If you're on a budget, you could pull the switch and clean it/try to fix it. Otherwise, I think Force 5 has them for about 20 bucks.
Owner of a Pearl White 1989 Audi 200QT. Pics to come soon.