Help! Drywall anchor doesn't go through metal
Normally I avoid them, but there's a "screw-in" drywall anchor (it's metal) that can work with studs. The one I have is called EZ-Ancor but I've seen others. You should be able to find a small pack of them and add one that will grip the stud. That might solve your problem because the screwing action of the anchor should fit in the hole you've drilled in the metal stud.