Need help for mandatory reconsideration for LCWRA

I was awarded standard living component and no mobility. I got my award letter 10 months ago, and recently I was told by citizens advice bureau, that I should have been awarded mobility component and higher standard living, and I realised I only submitted one piece of evidence (psychologist’s evaluation of my condition) and I didn’t submit any other evidence, like my partners/friends/gp’s letters. I do believe I would get higher award based on that, however I’ve missed the deadline for the appeal.
I do know there is possibility to ask for late re-determination (with a good reason) but I feel it’s so late.
I feel the best option is to report a change of circumstances, but my condition and symptoms didn’t get worse or better. They were always the same, but most of it I didn’t include during the initial assessment, and didn’t submit support letters.
I had no idea what I was doing at the time, and didn’t know I could speak to citizens advice bureau, but mostly I thought the assessors will get any information they need form my gp and previous treatments and diagnosis (I know it’s so stupid, I honestly didn’t know better at the time).

What’s the best and safest route to take? I do know there is a risk of losing the award, however I feel like my support evidence will give much more strength to my existing points, and potentially give me award in mobility, as CAB told me they are surprised I didn’t get it.

I am diagnosed with complex PTSD, anxiety, OCD, and emotionally unstable personality disorder (that was diagnosed for and treated in Poland, before I migrated to UK).

I now got support evidence from my partner (who is my registered carer) and my work colleague.

I received indefinite fit note form my doctor.

I am now in a process of arranging flexible working arrangements with my work (I work one day a week. Came down from 3 days a week, shortly after my ADP award).

*I do have CAB appointment, but it’s in one month time.