Bad Predicted Grades/Gap Year/Cambridge

Hi I am currently in year 13 and at the start of year 12 I had pretty bad grades but by the end of the year I was getting As in all my subjects, then lockdown happened and I struggled with the amount of work that was being set. So basically I was planning on applying to Cambridge for linguistics and my Spanish teacher has predicted me a D, I haven't been given my other grades yet but I spoke to him and he refuses to change it (he hates me). I know I have the capability to get an A but I don't know if I should just give up applying this year and apply next year? Or if I should just apply now anyway and hope for adjustment/ get rejected and apply again next year? Also I don't know if my sixth form would help me with my ucas application after I left?? Sorry, this is a bit of a rant but my head is all over the place with this, I wasn't expecting a D and I don't want to sound egotistical but I think I am capable of an A. Any help/advice would be much appreciated