hi chronic ear pain with  associated headache lasting for 2 years is unlikely to be because of negative middle ear pressure also known as eustachian tube dysfunction there two important conditions which can present similarly are 1. temporomandibular dysfunction - in this condition there will be pain in front of ear which is also referred indside ear and also associated headache. you have to consult maxillo facial surgeon if you have these symptoms 2. rarely  headache can be referred to ear especially tension type of headache and also migraine..that needs to be evaluated hope this information helps you