Starting about 2 weeks ago my headlights would get brighter when i gave it gas. when i noticed it i reved it up and a head light burnt out. then yesterday i down shifted to pass a semi then another headlight went out i replaced today drove 2 miles with the lights on nothing happend. went to leave 30 min later lights turn on a tiny bit could bearly tell they were on. inside the car said the brights were on but they werent when i tried to turn them on they turned on and it made a tiny bit of a difference. but the car starts fine i dont think the battery is bad the light inside the car is bright too. any ideas on what it is? please need help fast I deliver food. I need my car please help