You've got a shorted wire somewhere in the low-beam circuit. Check for a pinched wire on the side with the deer strike.

Possibly this could be bulb related, but I doubt it. You could unplug that light and see if the problem persists - if it's a pinched wire before the lamp, then the behavior will remain. If it's the bulb, the behavior will be gone. Try swapping the bulb for a known good one.