Instead of Gas-X, you could try alka seltzer, it releases gas from the tummy and also helps return the body from an acidic state to a more alkaline state. I used to get gas when I was younger and it hurt in my stomach, and a relative told me about alka seltzer.
Even tho you had an ultrasound not long ago, you might have developed a little ulcer, so they might want to do an endoscope down the throat and into the stomach to look. Also, could be you have an intestinal bacteria going, so you may need to give a stool sample and have blood drawn to make sure you haven't picked up some bug.
Congrats on the sobriety. I'm sober 25 years now, no way I'd go back to that wretched existence. I'm high on life.
First off, congratulations on being sober for 2 months! That's awesome especially considering you're in the middle of tropical party paradise. I completely sympathize with you regarding the pressure in your stomach. I couldn't even lay may own hand on my stomach when I slept because it would be so irritating and 'heavy'. The cause of mine was a little serious (ascites from severe liver disease from drinking too much - btw I'm doing very well now), and I'm sure it's much different from yours, but one way to put your mind at ease is to just go in for some simple blood tests. They can certainly tell if anything is out of whack from the results. Good luck!
Mike, the heartbeat near the left side of your bellybutton is the pulse from the descending aorta. It's typical to feel somewhat of a heartbeat in that location, and if you're slim it may feel more prominent. The only time to worry is when the 'beat' becomes very wide - indicating distension of that section of the aorta. A doc can tell you whether or not the 'size' of the aorta is normal or not.
You may want to consider trying some probiotics, which are the good bacteria you should have in your GI tract but may not have due to your liquid intake for a number of years. It may cut down on the gas you're feeling.
In addition, keep a food diary and see is any foods - other than diary - make a difference. If it's not lactose (the sugar in dairy) that's bothering you, then it could be the casein (the major protein). If that's true, then check with your family and see is anyone in the family is celiac (gluten-intolerant). If you have relatives with that issue, get yourself checked. Celiac issues can cause a variety of symptoms - and misery.
Also check the side effects from the meds you're taking. All meds have side-effects. It just depends on whether or not the individual is bothered by them.
And keep in mind that stress can have a BIG impact on the GI tract. Stress isn't just a concept. It's the phyical release of hormones that affect every organ in the body.