You have a few choices here.
1) Work your butt off over the summer and the start of next term - really work and don't just play at it. If you can produce higher quality work next term, your teacher may consider raising your predicted grade. Remember that you do not have to submit your UCAS application until next January, whatever your school tells you.
2) Work your butt off and get higher grades next August. Then apply for Uni during a gap year for 2025 entry with achieved grades.
3) Accept that you are not going to drag your grades up and apply to lower grade Unis - or another subject.