My headlight doesn't work after I put in new bulb.

I have a 2008 dodge avenger and recently the left headlight began to turn off on its own, i could sometimes get it to come back on by tapping on the headlight itself, but now there is no response. after replacing the bulb with a new one, there has been no difference. I would really like any help that you can give me. if this can be easily be repaired by myself at low cost or if I would have to take my car into a shop.