re taking year 12

i am currently a year 12 student studying psychology, economics and english literature. However, these options were my plan B as i originally wanted to take chem, maths and psychology but due to not hitting the grade requirements, i was not able to. I was suggested by my exam officer to retake chemistry and maths for gcse but for that I would have to repeat year 12 again. Is it okay for me to repeat year 12 and do you think universities would accept me to do medicine?