Don't let them rush you into dilation! That would only ruin the nice new "valve" they put in!!! It would also allow you to start refluxing again.
It seems they didn't do enough testing before rushing into surgery, which doesn't fix anything except the refluxate being able to get past the new "valve." Did they do the esophageal manometry to rule out esophageal spasms and such? Weren't you having these episodes before surgery?
It could be that you are having a reaction to trigger foods. They can cause problems as much as 24-48 hours after eating them, although in my personal experience I was getting a reaction within an hour, two at the max. I'm not saying this is your problem, but it may be worth checking out.
I'm sure you are still eating nothing worse than soft foods still, but even clear liquids can be a problem if they contain triggers. I knew my triggers before going into surgery and brought my own clear liquids because I knew I couldn't eat commercially porcessed broth and jello.
My personal trigger is sulfite (not sulfate or sulfa!). There are many websites that have good lists of food allergies and sulfite.
All processed broth has sulfite it's naturally in the garlic and onion and pepper. Gelatin is made from sulfited (softening agent) pork skin. A lot of fish and shrimp are sulfited to prevent spoilage right on the fishing boats - so I can't take fish oil for my cholesterol either. Ano so on and so on. You can look up lots more.
I would and did try eating only things I prepared myself from scratch (aka real food). I boiled up my own checken and beef for broth - no seasoning except a tiny bit of salt. I squeezed my own fruit juices (no grapes!). I boiled up my own vegetables - careful there! see lists - and squeezed my own vegetable broth. Likewise I used my food processor to make my own soft foods - not using anything that naturally contains sulfite.
If that doesn't work I would suspect something physical they didn't test for - maybe a problem with the valve at the other end of the stomach not working.
Also - remote possibility - the stomach can be triggered by the heart. It's cardio-esophageal reflex (not reflux). The stomach can trigger the heart and coronary arteries to spasm, and it can work the other way around. But I wold not expect that to be your problem!