I've had the exact same thing...right down to the funny burps. I went to a gastrologist, and he was an awesome doctor. After seeing him twice, he told me that I was really just using him for reassurance, and that my GI tract was perfectly normal (I had both ends oscopy'd if you know what i mean), save some evidence of gastritis. I'd also had diarrhea for about 5-6 weeks.
I would recommend that you take a good probiotic...it's help straighten out a bunch of stuff with my GI tract.
You aren't taking fish oil are you? That funny tasting burp could be caused by fish oil pills as well. I recommend taking them as well if you don't eat a lot of fish. I'm also taking some vitamin D as a supplement since we're just getting started with winter, and I'm not outside anywhere near as much as i used to be. Vitamins D & B are very important to overcoming anxiety.
I have also been having this problem. I have a lot of stomach gas, and when I burp it up it tastes strongly of metal. I also suffer from anxiety/panic attacks, but one difference is that I have been vomitting, and the vomit tastes a lot like some kind of pill, although I no longer take any kind of pill...help?