Hi there - it's hard, I agree it's hard. BUT rather than say oesophagitis is a lifelong disease, I would say that MANAGING it maybe a lifelong job! It should be a question of managing flare ups, rather than a daily impossible struggle. And if it's a daily impossible struggle you should be looking at different treatment or surgery.
On top of the many foods I exclude due to allergy, I now also have to excude food and drink which aggravate my GERD. It's not fun and it can be very antisocial, depending on whether it's in a good phase or a bad phase. But sometimes my stomach will tolerate things that I like - in moderation. We're all very individual in that respect. I am also coming to accept that symptoms can fluctuate regardless of what I've eaten; sometimes it's just outside of my control. What I would say is be absolutely sure that any dietary restrictions are definitely benefiting you and that you are not just assuming things are "not allowed" because of any particular diagnosis.
If your diet and lifestyle are so restricted that you are miserable to the point of not coping, then you need to pursue more treatment. Insist on having your medication reviewed and ask if you are eligible for other treatment or surgery, and if not, why not.
If, in addition to your physical symptoms, you are anxious, depressed (even if this is in response to your physical state) or not coping, then you need to address this too. Acid reflux does not take kindly to stress and anxiety - which is a bit unfair, I know, seeing as it's a great source of stress just in itself!
I really feel you need to speak to your GP/primary carer and say just how low you feel and that you need some other options or plan of action.
And I'm sure your fiance IS there for you - but you do need to tell her how you feel and that you need her support in taking some action to help you get better, both mentally and physically.
I do understand how weary you can feel repeatedly explaining why you have to have different food - that bit I have been doing for 25 years! Sometimes when I have people round for coffee I just sip hot water - they don't even notice and I get the social side without the heartburn!