do I need mitigated circumstance evidence during ongoing exams if i apply afterwards

I am currently doing a-levels rn, alevel maths, bio, chem, wanting to go into medicine. At the beginning of sixth form, I was doing great and decided to take a gap year after A-levels to clear up my head and do things I always wanted to do. Then I started showing signs of depression between year 12-13. I am pretty sure I may have severe depression, doing multiple depression tests, and having socially isolated myself from my friends, stopped talking to people, stopped enjoying my hobbies, lost interest in things, lost my motivation and will to do things, and thinking I have no purpose in life, and having thoughts of self-harm and ending my life, etc... I really want to do medicine though, but I know I will not get good results. I want to resit, but only a few unis accept resits for medicine and is really difficult and more competitive to apply for them.
The main problem is I haven't diagnosed yet for depression, and I regret not getting it checked much earlier. I would like to apply to my desired unis with under a mitigated circumstance but am not sure whether to get diagnosed for depression during exams? Or is it possible to get diagnosed after exams. Please help with my question

The most inportant thing is to get your mental health sorted out, then everything else will be easier to deal with, so please go see your GP to discuss things, it will be confidential and they can help you with the next steps.
Your options currently will be to see your GP, discuss with school and possibly not sit your final exams, as you are medically unfit, or to apply for special consideration to the exam board. This would mean you could possibly re-do Yr13 and sit your A levels next year. This would still mean you would fall under the resit policies for most med schools, but it would not limit you in terms of first-sit minimum requirments. There are quite a few med schools that accept re-sits, but many want AAB or ABB for first sit, so depends if you think you will make that. If not, it would severely limit your options.
You can apply to med schools for ExCircs, but they would still want you to resit and obtain the entry requirements, but it may mean they waive first sit requirements or resit rules. However, I think corroborating evidence is going to be difficult, if you have never spoken to anyone about this, so may not be accepted.
So first step is to see your GP asap and consider speaking to school about whether to not complete your exams as not fit or whether you can re-do Yr13, if needed

thanks for the advice. I didn't realise you can do that, but there's no way my parents would let me do that. I'm going to get forced to finish my exams anyways. I'm just trying to do all I can at the moment. 😕 I dont think gp will let me see them this time too, because of how long the waiting list is. Soonest I can see one is after exams end. Thank you so much for replying though, there's barely any information regarding this ❤️