Strangest Headlight Problem

Hi, first time posting but I've been a guest on here for a while keeping up with conversation. I have a 1983 300D Turbo and I had the weirdest thing happen with the headlights tonight. Somehow, the high beams got turned on but then STAYED on, indicator light and all. There was nothing I could do to turn them off. They even go on by themselves when the key is in the on position and the headlights are OFF. During the day it would be like driving with high beams on for daytime running lights. As far as I can gather, they stay on in tandem with the regular lights, and when I flick the turn signal stalk away from the wheel (as if to turn the high beams on), the regular lights go off.

Strange isn't it? I can't keep on driving like this, it pi$$es people off, but I don't know how to turn them off or what to do.

Please help!!!

Thanks so much.

John