Interesting! I have had Eustachian tube dysfunction myself. It's quite terrible. The worst part for me was the vertigo that I got. I literally can't move when it happens, I'm so dizzy and nauseated. I have 'flare ups' of it. I get fullness in the ear too and muffled hearing. The fatigue for me is just that i feel so bad I have to lay with my eyes closed. And I wonder if your neck and arm pain is from tensing? I never had any musculature involvement other than I would lay there or hold my head a certain way to try to make it better and my neck might get stiff. Think about what Eustachian tube dysfunction is. Basically, the canal closes in on itself. How would that affect your neck muscles? or arm muscles? Probably would not. That sounds either from tensing or anxiety. Anxiety with it is real because when I feel that fullness starting, I get a little panicky. I don't want to have another episode! I don't get tired from it either. I do lay there and sleep because it helps the vertigo. But it's not an illness, so it doesn't have symptoms like that.
Now, there IS a virus that can cause similar symptoms to Eustachian tube dysfunction called labyrinthitis. https://www.webmd.com/brain/what-is-labyrinthitis#1 It causes ear fullness, vertigo and various other symptoms. Not sure you'd get it over and over though. I do have a friend that had it and it led to Eustachian tube dysfunction.
Anyway, I have not had an episode now for years. (knock on wood). I visited an ENT and the things that helped me were reverse ear pops (hold nose, blow gently. Repeat over and over. Ears pop). Taking an antihistamine like over the counter claritan. Sometimes taking pseudophedrine. Chewing gum. That really helped me. And for other people, there is a manipulation that ENT's do that can help. https://familydoctor.org/condition/eustachian-tube-dysfunction/