headlight go out every month or so

well ever since i bought the car (last August) i have had to replace one of the headlights in the car about once a month. after several pairs of bulbs and many different combonations of makers i thought to ask you guys if you know what is going on. also only one of my fog lights is completly out and in not even getting power and one of my taillights only comes on when i press the brake. thanks if you know something that i don't