hiya debz. I had something similar with all those sypmtoms plus I also had overbreathing (where you don't think that you will breath if you don't think about it, but then you breath too much oxygen and get a bit dizzy and the floor feels like it's moving. I was ok when I was asleep, and when I was exercising. The quacks couldn't work out what it was: they put me on beta blockers, and then travel sickness tablets for the nausea and moving floor. I gave up going to see them as neither helped.
I found out by a process of elimination,that I had an intolerance to caffeine. I'd drunk coffee, tea, coke, redbull, proplus etc fine for years. But as with anything, sometimes too much can either stop something from having any effect, to your body becoming intorlerant. I think what was happening was that the caffeine was making my body produce too much adrenaline, which it does naturally when you go into fight or flight mode. Because, I was doing neither of these it caused the effects of anxiety. That's probably why I was ok when I was exercising.
Just stopping taking caffeine can cause other effects - headaches etc. Maybe reduce over a week and then have a day when you don't drink tea, coffee or coke and see if it helps. If not then it's probably not caffeine, but might be worth a try, as I've found a few other people that have had similar symptoms when they'd been fine drinking coffee and tea for years. Oh and btw Green tea has quite a bit of caffeine in it too. Fruit tea, red bush tea, herbal tea etc are ok. De-caff tea and coffee still have a small percentage of caffeine so 3-4cups can give the same effect as one cup of regular.
Hope this helps, and you feel better soon and try to relax.