I do flights very similar to you, Portland to Newark, Newark to Birmingham so it's roughly 5 hours for the first and 7 for the second. I always feel like death warmed over when I see Steve if it makes you feel any better
But I carry small amounts of makeup in my carry-on so I can reapply it for when I get into the UK, it makes me feel more human.
But I understand your anxiety especially with an ear infection
Definitely take some meds with you to try and relieve pressure/dull the pain if there's anything that does that for you. I try taking Tylenol PM but I'm too nervous/excited on my Newark to Birmingham flight for it to work, but it might be enough to help you sleep. And definitely find things to occupy your mind--I've been told to pack a 'goody' bag for my carry-on with magazines and books with lots of pictures to take your mind off of things (pictures can be much more distracting than words), music, just whatever comforts you as long as it's TSA friendly of course
My anticipatory anxiety is the worst, the last few days before I fly out--my stomach doesn't like me, and I normally get about 3 whole hours of sleep the night before I fly out. But when I get to the airport I'm actually really excited, since it's one step closer to seeing Steve--let that excitement of seeing your fiance overcome your anxiety