I have had a migraine for 4 days now & the pressure behind my eyes is horrible. I'm 51 yrs. Old. Upon waking up after a restless night I am temporarily painfree until I eat something, then the headache is back as well as the pressure.

Could be muscle pain. Muscles in the mouth can tighten and send pain into the area behind the eyes. If you have already been under treatment by a md, you might benefit from a visit to a dentist trained in neuromuscular dentistry. How do I know this? I had similar symptoms until properly diagnosed and treated!
Any . Any ha lasting this long should be evaluated by the ed or with imaging to rule out any more serious cause. Talk to your doctor or go to the ed asap.