Problem with headlight bulbs

Hi, I have a situation where I get an indicator light telling me that the high beams are on and my headlights are out and I have no control over the lights when this happens. When I lift up the hood and tap the back of the plug that plugs into the bulb that goes into the headlight unit itself the lights come on both headlights come back on when I do this. After having to do this several times tapping the back of that this started not to work anymore. When I jiggle it around the lights come on but there is something that seems to be loose inside the back of that one bulb that is causing the problem or I could be wrong. One thing I am not understanding is why that particular piece or wire that is either loose or malfunctioning has control over both headlight bulbs by making them both go out from it being loose or whatever it is wrong with it. Can anyone instruct me on what to do will it help if I change the bulb in this particular headlight which is on the passenger side? It is very hard to access because the air conditioning lines are in front of it. However, I saw an instructional video that shows that the whole headlight unit itself comes out from the front after removing the grill and some other attachments that are holding it in. I do not really want to mess with it myself but do not have much money to do repairs and I am afraid to cause more of an electrical problem if it is a loose wire that is causing both those bulbs to go out. I hope that I describe this clearly by no means I am a mechanic and do I understand the technical terms to explain these parts correctly any bit of advice or help will be greatly appreciated. This is a great site, a great find for me that I will be tuning into for sure in the future.