Identifying the T that causes the F of anxiety

Dear coaches

I often feel anxious at the weekends when I’m alone and I seem to make it a problem. There’s nothing ‘wrong’, or, rather, no neutral C’s that I am having negative T’s about. There’s ‘no reason’ to feel anxious.

I have done many thought downloads on this I often cannot find the thought causing the anxiety as such, more a bunch of thoughts about the anxiety, which seem to be exacerbating the ‘problem’.

I shouldn’t be feeling anxiety
It’s not fair that I’m feeling anxious when I have lots of great t’s about my c’s.
It’s not fair I should have to ‘suffer’ when there is ‘nothing wrong’
I’m annoyed I cannot find the T causing the F of anxiety [so I can fix it]

C: vibration in body
T: I shouldn’t be feeling anxiety
F: frustrated / victimised ( I know we only use one F but is victimised a feeling?)
A: think about all the other times I have anxiety, match up ‘patterns’ (like I ‘always’ have anxiety at the weekend), think I need to self coach rather than do scheduled tasks, don’t look for ways I can enjoy the day, believe the day cannot be enjoyed because of a feeling.
R: Create more anxiety

My question is: if I think my anxiety is perpetuated by the belief I shouldn’t be feeling anxious and that it’s unfair etc, where does it ‘come from’ in the first place, if our F’s are created by a T in our mind?
Like, I think my T is ‘I shouldn’t be feeling anxiety’ (or version of entitlement to an anxiety-free existence because I have ‘a nice life’ with no ‘need to be anxious) about the anxiety, but how is the anxiety created? A T in my mind?

Can you show me how I can work on my anxiety if I can see I am perpetuating it, but can’t see how I create it in the first place?