Resit attempt without proof of circumstances, what are my chances.

So, I am currently a private candidate re-sitting A-levels. I am hoping to apply for University of Edinburgh Finance and Business. I am currently holding A*A*A as my predicted grades after sitting a few mocks in an exam centre. However I know UOE has been quite strict on resit applications, so I am quite unsure whether I should spend 1 application spot for UOE.
There is a huge downside however, which is that I don't have a certified proof for my circumstances. I kinda knew what went wrong last year. Last year I did 4 subjects, held predicted grades of A*AAB and received an offer from UOE psychology. At the same time I was also participating in other curriculums such as music competitions and choir performances. Plus, I got into a relationship. I overestimated my strength, and underestimated the difficulties of the course.
This resulted in me getting everything wrong. As the pressure builds up through year 13 (as the course gets harder to understand) I developed sleeping problems and anxiety. The downgrade of mental health also reflected on my body as I was always sick throughout the year. I got totally overwhelmed and everything went wrong. I lost the competitions and screwed the performances, broke up, and got horrendous results in the actual A levels. The most painful part is that, I came from a kinda typical Asian family, where I couldn't really open up to my parents or anyone, not mentioning going to a psychiatrist and have a formal diagnosis, as it will be considered as a complain and being ungrateful to what they provided me.
This year, I decided that my personal health goes first. I hit the gym, did yoga and played tennis regularly. I also went out more and touched more grass. I built timed revision periods with a consistent schedule as well as doing extra learning by joining courses on the internet such as CS50. I even learnt cooking. Everything is better now, I have an even higher predicted grades than last year. However I still can't open up with my parents, and still I bear the cross of not trying hard enough last year.
This is my conditions summed up, however, for the required documents of proof of EC, formal diagnosis from counsellors or psychiatrist seems like a dead end for me. Can I still get into UOE? Any honest or even brutal comments could help, thank you all very much for reading such a long bunch of words.