Headlights went out one after the other

I guess you are saying that after you turned the ignition off, the headlights and all lights went off, but when you returned and turned ignition on all lights but the headlights came on. "a gremlin" stole my light switch? Possible, but most likely your headlight switch is bad, or the headlight relay, or if the dimmer switch makes no difference, It could be power supply or connection to the headlight dimmer relay is bad. Corrosion causes funny behavior. Clean bright metal connections make a world of difference. Follow headlight wiring back to a small box usually on the inside fender of the Engine bay. Check all connections including the ground to the frame (body metal).

there is a few fuses for the lights

Depending on the year and model Ford, there could be fuses for the headlights, or a circuit breaker inside the headlight switch.
The dimmer switch could have failed.

All types of car headlight problem troubleshooting.Click the link below :---All headlights not working? http://repairhelpcenter.blogspot.com/2012/01/all-headlights-not-working.html
---------This will help.Thanks.

if both headlights went out at the same time, check your fuses. because high beams use more power than headlights, they are often on a separate fuse. if fuses are fine, replace the headlights.

Not exactly sure where to look but there may be what is called an in-line fuse-link. It would be somewhere in the wire going to the headlight. Basically a fuse but not in a fusebox. I would look under the hood and trace the wire from the headlight.

pull the headlight switch out and check it for any burnt looking pins or a burned connector hard shell.

are the dash lights blinking on and off also when this condition happens, or is it just the headlights?

there sounds like a deffinant short some where. you'll need someone that knows electrical to find the sourse. sorry

The headlights on the envoy are the easiest parts of the car to repair. You just pull the two tabs at the top of the headlights, screw out the bulb containers and you are good to go