Is stress what's causing this?

I know exactly what you’re going through! For me it was due to too much stress over a long time, along with some derealization (also caused by stress). I won’t be much help in telling you and immediate cure, since for me it was mostly time that made all the symptoms go away. It really is awful, though, when you have it. All I can suggest is to try to relax as much as you can (some of the breathing techniques really do work) and ignore the symptoms as much as possible. And talk to someone! This always helped me when I was super stressed.