chronic stomach pain

Im a 15 year old female and for about the past 2 years I've had regular stomach pain that is becoming more and more common. it hurts in my middle to lower abdomen, and is a little bit  crampier on the left side. the pain is sometimes brought on by if i become hungry, and then if i eat it gets even worse but sometimes its just completley random pain. the pain is disabiling, and the only thing that makes it feel better is lying on my stomach and even then its still really bad. i think it may be brought on by richer foods but i dont really know. should i seek medical help and what do you thing is wrong with me if anything