Hi. Well I don't have social anxiety so much. But in certain situations I naturally sweat more, for instance if I'm supposed to speak in front of a hall or something. Also if people are abruptly "in my space" I may get on high alert or some such, since in the past I've found it tough letting people in my space since at one point I had more serious odor than I have now and others have said things of course.
I highly doubt though that social anxiety has anything to do with odor. Of course anything that gets you excessively nervous will affect the stomach a little bit. However, if you're not constipated than for sure I would worry about a spinal injury, or look to see if you could be diagnosed with Multiple Sclerosis, which both affect the bowel control. Also, I may get your kidneys checked by a medical doctor, and check about any possibility of diabetes.
I have a question though. Do you sit most of every day due to tyring to "contain" your B.O.? I've found for myself that sometimes it's more comfortable to sit around people than to stand around people. This is because it's almost like a "lack of protection" when I stand up in some situations (I'm hardly a cripple in that regard though, I don't have trouble going out). But, the trouble is, if you sit down all day and don't have a job where you're up and about, then the spine could develop problems. And those with agoraphobia (those who retreat from all the bad situations rather than staying there and having anxiety) have a higher chance of developing the earlier stages of Multiple Sclerosis. Multiple Sclerosis in my opinion can easily be cured by never allowing yourself to get isolated and consuming the proper dietary nutrients. It's very important to get a job on your feet, and it's important to get outside a lot and into the "mainstream of society" so to speak. Going "out into the marketplace" is the best way I can describe it.
To correct your odor, I would definitely try to improve the diet, I would look at consuming the good bacteria found in yogurt, I would eat more fruits and veggies, I would get more exercise regularly, I may even consider herbal formulations to get rid of parasites. For instance, Black-Walnut hulls, and cloves etc. have been recommended by some top authorities, although I myself don't know if they work or how they work. I know this goes without saying, but just remember to shower every day and brush your teeth every day, and maybe even do both twice a day. I would consider adding Vitamin K via spinach and good bacteria. And above all, take it easy and relax.