Neck pain is hurting me so bad!!?

I'm a 13 year old girl. I have extreme neck pain. It all started Thurday and now it's Sunday. I was doing homework at home, sitting like I sit everyday for as long as I remember. All of a sudden my neck hurt so bad. I've never had such a pain before. And it was so quick! It has nothing to do with my period I'm for sure about that. I've tried everyhing possible I think. Hot showers, cold showers ,asprin, pain reliever, cream for just what I have, ice, hot packs, icey hot. It all just doesn't work. Not even warm or hot baths with my neck in the water or warm or cool cloths dd on it. The only thing that helps is the heating pad but as soon as it goes off or I move it's back to hurting. My mom woulnt take me to the doctor. She said to deal with it. It's getting better but it still is an unbelievale pain. It's just the middle back part and the right side that hurts though. I have school tomorrow and a 3-4 hour after school field trip Tuesday. What do I do? Please don't give me that thing about maging it becuase I've tried it to many times to count. PLEASE help! I've been praying so much!