I am sorry that you are suffering. You should ask your Gasteroentrologist for an endoscpy. My problems started few months after giving birth as well, I have hiatus hernia and GERD. I was also infected with H-pylori bacteria. Ther is ablood test which can be done for that. There is also cure for the bacteria, combination of 2 types of antibiotics and PPI.
The worst thing for your condition is to stress so much. Stress can make it worst. You asked about weight, well I know they say that being overweight can cotribute to Reflux.
Try gaviscon advance it does help, and pleaseif possible try to see your doctor. Please don't be scared, I know how you feel, I am on 80mg of nexium and still suffer ona daily basis, but thankfully there is nothing bad happeing inside of me. If you read all the posts here you can see that there are loads of people with the same symptoms as yours, but nothing life threatening is the cause of it.
Hope you feel better.