Yes, feels like anxiety and just might be but I believe it is the inability of the autonomic nervous system to regulate itself. Your symptoms are pretty pronounced. I'm a big believer that everyone with CFS should have an Brain MRI with contrast. The contrast is important because they cannot see tiny tumors on the pituitary with regular MRI. I think that might put you mind at rest about the brain tumor if you haven't already done it.
I started having migraines and my neurologist found a partially empty sella that is a result of the infection i'm sure. That is when the membrane around the pituitary gland is ruptured and the spinal fluid starts to leak in and flattens the pituitary. My understanding is that some CFS people experience this. I should probably mention that pituitary tumors are almost always benign.
It's certainly worth checking out.
Wish I'd known to ask about the contrast MRI - just had one done which showed nothing - so my neurologist said over the phone - I suffered from horrendous pressure having to lie down in the scanner - for nothing it seems. Life with ME.