Hi ArbyBarbie!
I've lost a very similar amount of weight due to GERD (normally around 118, now down to 102 and looking bony!) -- it can be hard to eat enough calories when you're feeling sick, or even when I don't have many symptoms if I eat too much it can cause GERD symptoms! My doctor thinks anxiety is also playing a role in my weight loss, so even though it's difficult, do try to calm down if you can :) You could certainly ask for a referral to a GI doctor or find one on your own if you don't feel comfortable with what your family doctor is doing! I saw my family doctor for several visits until he referred me to a GI to get an endoscopy done; now I go back and borth and see both doctors since they both want to keep an eye on me :)
While I'm obviously not a doctor, the fact that your symptoms are worse when sitting or laying down could indicate GERD. When you sit down, it can put pressure on your stomach and cause acid to back up, and if you have a hiatal hernia (like me!) sitting down can put pressure on the hernia. When you lay down, gravity makes it easier for acid to back up. My symptoms usually feel the best when I stand up, walk around, or lay on an incline or recline.
I originally tried Prilosec and it did nothing for me. I finally found some relief by doing the following things:
* Taking Nexium 40 mg
* Sleeping on a wedge pillow
* Eating smaller portions more often
* Changing my diet to exclude common GERD trigger foods (caffeine, alcohol, carbonated drinks, spicy foods, onions, garlic, tomatoes, citrus, anything really acidic, chocolate, mint). Every person has different trigger foods so it may take some experimentation to find out what works for you, but these foods might be a good start if you have no idea what your triggers are! However, previously I was eating *at least* 2 or 3 of these foods every day, and within 24 hours of starting this diet one of my main symptoms (chest pain) drastically improved!
* I also get more symptoms when I'm stressed, so I'm working on dealing with my stress and anxiety! But sometimes you just can't avoid stress ;)
While I have yet to gain the weight back, I have been able to maintain my weight for at least a month now so that's a start! While dairy and fatty foods may cause GERD symptoms for some people, I try to eat as many calories as I can without causing symptoms -- I've actually been eating more dairy lately (yogurt, cheese, etc.), nuts, avocadoes, other healthy fats, some fried foods (but too much grease makes my stomach angry!), etc... Basically whatever you can tolerate :)
You may have to start slow until you get your symptoms under control, and yes, it may take a while until meds start working -- good luck and take it easy!
PS: My GERD started when I took doxycyline (an antibiotic) for a few months for acne. Now I wish I wouldn't have let my dermatologist talk me into that! :)