Medicine or not?

Hi,
I am starting yr 13 in September i am predicted BBC in biology, psychology and chemistry. I got an A in biology and A in psychology and didn’t do good ay all in chemistry got an E- the subject i was revised for the most- anyways i was hoping to go in medicine and i have booked my UCAT. Leeds is my top choice and the entry requirements are AAA. I am really really stressed and I don’t know what to do.
So if i do amazing on the ucat and doesn’t do as well on my alevels- i wont get into uni.
If i get AAA in alevels and don’t get the required ucat score- i wont get into uni.
I am extremely stressed and unsure of what do with my life.
Anyone who could help it would be really appreciated