You definitely have GERD. If Nexium isn't working, take 2 of them or get a prescription for protonix or a stronger version of Nexium, aciphex, or lansoprazole. Protonix is really good. If it does not relieve your symptoms, get a GI consult and ask them to do an endoscopy if indicated. It could be a hiatal hernia, but its a stretch. Id bet GERD 99%.
Firstly, I hope you are a non smoker as that can be one of the major causes contributing to your problem. Secondly, It is a good idea to note down and stick with the foods or drinks that seem to be easily digested without causing any acidity issues, as well as maintaining a healthy sleep pattern and good food habits, such as not drinking too much water after you are done with your dinner or lunch. Don't over eat or eat too less at a time. Always maintain a gap of at least 1 hour before you go to sleep after dinner. I have noticed that soups, especially the ones with too much spices or even otherwise don't help a person with acid re-flux issues. Lastly your acid issues may be related to IBS (irritable bowel syndrome) which may need a further diagnosis and is closely related to the state of mind a person is in. Anxiety may contribute as a problem there.
In addition to this, I would suggest mild exercise and breathing exercises to help you further with your metabolism.
Watch out for milk, coffee, soup, sodas, oil, beer, sugar, egg yolk, pulses,etc for sometime to avoid .
There is a herb called "" Glycyrrhiza glabra"" which can help you with gastric comfort. You must try the vegetable Bitter Mellon low fried in olive oil with some well cooked plain rice for lunch/dinner and notice how well it suits you. Hope It helps