Resists?

Okay so I'm really upset about my GCSE I'll likley only get 3As 4Bs and 1C but I really wanted to be a optometrist or a biomedical scientist. I actually had a lot of problems. Due to some cricmumstances I had to change schools in the middle of year 11. I hate my life right now. I want to take a resit in maths in November to atleast get a B my collage claimed that they'll put me in a special course if I want it, the main question is how do universities feel about November resits?
Then I see people crying because oh no they've gotten a B in something and people have amazing GCSEs like 6As and 4A*s
So how do universities feel about GCSEs and resist in general? I was more then capable of achieving As in eveything even my teachers have said so but changing schools in hers 11 is stressful!