Low breams don’t work and high beams?

Low breams don’t work and high beams? Sometimes my low beams don’t work but my high beams do. Sometimes they both work. One night a few weeks ago the low beams didn’t work but my high beams did I got out of my car slammed my door and the low beams flicked on. About a year ago I hit a deer and I got a new bumper my original bumper didn’t have fog lights and this one did. This problem hasn’t started just till a few weeks ago but a couple of car savy friends think it might be the fog lights.