My headlights blink on & off as I'm driving down the highway! Can't drive at night anymore because of this!

1) Get out your owner's manual and turn to the fuse panel diagram
2) Locate and replace the fuse responsible for your headlights (might be separate fuses for each headllight)
3) If this isn't the issue, it's possible a relay is bad. They should be located with your fuse panel and can be replaced easily. You can get them from any auto parts store for a modest price.
4) If you've replaced the relays and the fuses and still have the issue, it's possible it's the GEM module. This is quite a bit trickier and you'll likely need a qualified mechanic to replace it. I'd recommend taking it to a mechanic before trying the GEM module because it might also be a short in the wiring. Either way, leave those jobs for the pros.