HELP PLEASE! Wrong a levels can’t change-need advice.

Hi! so I’ve just started my a levels in September. I received my Gcse results and did very well, including 100% at the new AQA Art and Design course-a grade 9. I have chosen my a levels as biology and chemistry (enjoyable) geography (not so much) and psychology (awful) my school still do the 4 AS exams and you drop one to do 3 A2’s in the AS’s you took (pointless but just how they still do it) and I am totally regretting taking psychology-I knew I should have taken A Level art as I now know I want to do a degree which uses said art, as I naturally have a “talent” for it; my school gave us a deadline to change subjects as the last Monday of September-after just 2 and a half weeks of lessons. However, I’m having a problem as I missed the deadline. I began my appeal to change to art (from psych) 2 days after the deadline ended, and no matter how many times I tell them I will catch up, I need it for my degree, I need it for my future, I have the dedication to independently work on it for a long long time in order to catch up, how I regret my choice and how depressed it’s making me that I can’t do what I want to do in future-they wont budge. 😑They won’t let me take it AT ALL😡. And their reasoning is because “the art teacher doesn’t have enough time to tutor only me” and my only option is to do the A2 Art in a gap year, or do the full A2 in one year. Everyone I talk to thinks this is ridiculous as these ‘compromises’ are unrealistic as I’ve only missed about a months work-which does not equate to an extra year. They told me they would have one final ask with the art teacher tomorrow to see if he will ‘give in’ but say it’s very unlikely. I’m confused, upset and feel like I’ve ruined my future- I need to do art! I’m just not sure what to do and feeling so lost, I feel like their suggestions are ridiculous and that they don’t care that this is my future? I know I’m an idiot for not changing 2 days before I asked but I don’t think I deserve to not do what will get me my degree I want?...... A new kid joined our school just on Friday (y12) and was able to do every subject he wanted-including DT which is part of the art and design department. Any advice on what to do or say would be much appreciated... thank you! 😌