Headlight help

Both my low beams blew out in the bulbs.

When I was coming home last week I had the high beams on, turned them off when I came to an intersection that was surrounded by street lights, and when I came to a dark area I realized my low beams were not on.

All other lights were working at the time and still do.

I had pulled the dash about 6 weeks prior to fix the gauges- so my assumption is the dash switch grounds the headlamps, is this correct?

I'm a dummy if that is the case.
I actually ran a ground wire from the dash to the gauge cluster because 2 of the dash lights were not working, and that solved it- those little screws holding the dash in are a poor ground at best- and I didn't even realize the light switch needed to be grounded.

I replaced the dash switch, the dimmer switch, then I looked at the lights and the bulbs looked a little cloudy- pulled them and confirmed.

I'm staring at the wiring diagram and I can't believe I wasted $45 bulbs.

So am I as stupid as I think I am, or is it something else that caused these bulbs to go?