Elastics class 3 hurts so much causing me a sever headache ! what should i do ?

Pressure = Pain: Unfortunately the pressure of the elastics are tugging on your teeth and jaws, giving you your headache. Have you just started wearing the elastics, and have you tried otc pain meds? The slow gradual pressure is needed to move your teeth... Once they start to move, much of the discomfort should be alleviated. I guess this is one of those "no pain, no gain" situations... Feel better soon.

Depends: Depends on why you are getting headaches. If it is just tooth movement then take antiinflamatories like advil (ibuprofen) or allieve. If there is a tooth interference a bumper might have to be put in to allow the movement. Talk to who ever is doing your braces.

Check with ortho: Talk to your orthodontist. Controlled forces are very important, also you want to avoid dental root resorption by any means.

Call Orthodontist!: I would recommend first calling your orthodontic office and seeing what they recommend. If these elastics are newly placed, then some discomfort is expected. Try advil (ibuprofen) for pain and see if it goes away. Your doctor is your best bet!