in the eye while using contact lenses can be due to corneal trauma or infection. It can also be due to a tight lens (less likely with soft contact lenses).
I would suggest you visit your ophthalmologist as soon as possible. in the meanwhile, do stop using the CLs but do not discard them. u can use ur spectacles till then. topical lubricating drop will help in reducing the irritation. simple pain killers should help with the headaches
hope this helps.