Sorry t hear about your problem.
The pressure on the diaphragm & the 'swollen' feeling are likely related to your acid reflux disorder.
Idially, you should get a recent endoscopy to rule peptic ulcers & H pylori infection in the stomach which can worsen acid reflux symptoms.
Since, you are abroad, you can increase the dose of omeprazole to 40 mg twice a day till you are able to see your doctor.
This dose will control your symptoms effectively.
Avoid coffee, alcohol, smoking, hot & spicy food.
thanks for the speedy reply!have been checking online for possible answers and get things like Hiatal Hernia:
is that a possibility or are the symptons more likely the result of long time acid problems as you suggested?
Very good concern.
Hiatal hernia is also a possibility, which is diagnosed with a CT scan of your abdomen.
Long time acid problem is more likely in your case.