[Need advice] Possible to study Computer Science in Cambridge with only A*A*A?

I am an international applicant and studying computer science in Cambridge has been my dream for so long, however my home country's qualification is unlikely to get me in, so from last October I self-studied the Edexcel International A Level and got my result few days ago, however the result completely broke my plan, I only got A*A*A(M FM Phy), the grade boundary was raised around 25% in my exam which A* in last series is only a B for the same raw mark in this series + there were a marking error in my script but they don't fix it even I applied for review of marking, and after all even I gave some margin when I was preparing for the exam it's still an A, I was fully into preparing TMUA and personal statement that I never thought of such thing would happen, I am now thinking should I just give up or what, coz I've seen people in TSR and reddit who got 4A*s and still got rejected, and my A*A*A is not competitive at all compared to those applicant, I do get a opportunity to resit in October, however despite top university like Cambridge don't like resit, the result will only come in mid Jan earliest, and at that time I think the decision will already have been made such that my late coming third A* will make no difference at all, I am now so hopeless that I don't know what to do, is there anybody here has experienced similar thing and can share your experience? Thank you so much