I've been having a sharp pain on my back, where my neck and shoulder meet, please help?

[omgDUDE.]

I'm 15 years of age, and ever since i could remember, i've been having this sharp pains, on the back of my left shoulder, reaching up to my neck. it started hurting ever since i was about 6, i remember i would always complain to my mom about it. and til' this day, it's still hurts, EVERYDAY. and i'm not exaggerating, it really does hurt every day. i can only sleep on my stomach, any other position would make it hurt even worse. i can't sit down unless i'm leaning on something, because it starts hurting. sometimes there's just a small pain, sometimes it hurts so much it makes me want to cry. Aspirins never seem to work. It also hurts if i start doing dishes, even if i walk for a long time. for example, every time i go shopping, it always starts hurting, really bad. i hate it. what could be wrong? i just ignored it for a long time, thinking it would go away. But it hasn't. i have YEARS with this pain, can anyone help please? oh and by the way, i never had any kind of bone fracture, or any accident that would cause it.