Hello, my warmest feelings for your concerns. I'm type 2 rather than T1 like yourself and for me diagnosis wasn't pivotal to my mental health story; but I hope there is something of value for you from my experience.
First, we're all weird and I've known a number of people with something that they might have described as 'weird toilet anxiety'; I will say what lots of people will say because it bears repeating often: 'be kind to yourself.'
I have suffered from anxiety and depression for more than half my life, probably since my late teens. It's only now on reflection that I have the suspicion it might have been physiological and to do with metabolism and blood glucose.
I think CBT is good and its practice has helped me enormously, sometimes though, practitioners have been awful; there was a lot of kissing of frogs along the way. I have tried lots of different drugs to marginal success, for me mirtazapine worked the best but with horrible side effects. CBT helped me manage, live in the world but I never felt like it made anxiety go away. I had a therapist who said the book 'feel the fear and do it anyway' was great if you only read the front cover. CBT never made the fear go away for me.
I had good and bad times which came and went and I wondered about being bipolar: having euphoric highly productive times and having deflated times where I was looking at reality through the wrong end of a telescope. I never came to any conclusion. I managed but I was disappointed at not feeling right.
Five years ago I had my diagnosis of T2DM hba1c 66mmol/mol, in the last year or so I've have reflected on the past and I find it plausible that fluctuating metabolic processes were a prime suspect. I think disposition, who I am, affects the prevalence; in the midst of lockdown my hba1c was 109mmol/mol.
My recent hba1c was 44mmol/mol which coincides with a period of serenity I don't recall having for a very long time; I mentioned mirtazapine earlier: this period of glucose control is much better than when I was taking that drug.
I don't wish to say that my mood is a simple function of glucose control, there is so much complication. I also can't really say which way the causality goes, probably a vicious cycle or virtuous loop depending on the direction.
I wish you well with CBT, if you trace back you can follow it all the way back to the stoics, so thousands of years of testing. I'd also support keeping an open mind: test other therapies. I believe I got stuck thinking my my mental health was purely rumination and how I thought about things. Now I suspect a physiological component. I was told a story of someone's mental health problems being down to a carbon monoxide leak, I wish I could find something so definitive.
Life may be easier without anxiety and depression undoubtably but it is part of me and I don't want to be at war with part of me. I hope you can be sanguine about your mental health trials.