Why would you need couples guidance? Is she doing anything that increases your anxiety?
I know if someone told me they were feeling and acting like you I would be out of there, particularly if I didn’t think I was displaying any behaviour that should be of concern. Thing is if you actually did trust her 100% that would allay your anxieties, even if you were just transposing some past trauma onto her.
I have no issue with acting in a way to reduce a partners worries, trust is something you have to earn and that’s natural. I would be talking to my GP, or even one of the talking mental health helplines about some of the talking therapies, and perhaps look to address your issues quick. So employers have access to confidential counseling for free, and it doesn’t have to be work related issues you see them for. I can’t help think given how extreme your reactions are to the anxiety, somethings going to crack at some point, so best get it sorted and get on with having a good relationship.