Why when i sleep on my right side i get a mive headache plz help!?

They started about 5 years ago. I could not figure out why i got them but recently i found that it's when i sleep on my right side. The headaches are unbelievably painfull. It starts with a tickle in the back of my throat then i start to feel a slight burning feeling on the right side of my head. Then it fells like my whole right side of my head is on fire. Sometimes they get that bad that i can not see and i feel sick please help i can't take them much longer. :(