Hi Littlea and welcome! I am sorry that you are having anxiety/stomach issues. As you can see from our posts, it is a common problem and you are not alone!
One other reason for having gas build up that I don't think was mentioned here is air gulping! It may sound strange, but when a person is anxious, he/she may unknowingly over-breathe, and swallow air, which then builds in the stomach causing bloating and belching.
Please don't ever feel ashamed for not being in control of anxiety! It is just and issue that has to be addressed and treated, like any other health concern.
I encourage you to keep posting here with us...and even start your own thread of introduction here if you feel comfortable. (this is a rather old thread, and you may get more responses if you start a new one!)
Take care, and look forward to getting to know you better
Scaredy Cat