defo doable - are these the only gcses you are taking? because for med i believe you need 6/7 gcses? could be wrong tho
tell us your exam boards and we may be able to give you more suitable advice
for maths, i used maths genie. it sorts out all the questions based on what grade you want so i think this may be helpful for you so that you can see what grade you're working at. i just repeated these questions again and again until they stuck in my head
for science, i used cognito. this was probably the thing that enabled me to do as well as i did in my exams. it sorts ppqs by topic and difficulty. i also used flashcards which i made based on the content from the website physics and maths tutor, cgp revision guides and past paper questions i didnt get full marks on (question on one side and mark scheme on the other - this helps finetune the language you use in your exams so that you can pick up all the marks off the mark schemes).
for english, i used a youtube channel called first rate tutors which helped me SO MUCH. the woman is an absolute legend and ik she has stuff for other exam boards too. i would also reccomend lithcharts for any novels you are currently studying. i didnt use it at gcse but i wish i did as im using it for a level and its amazing. decent analysis and great summaries for the texts with notes on themes. course hero is also really good at summarising novels and helping your understanding of the plot. also, really utilise your teachers. do ppqs and kindly ask them to mark it for you. usually, theyre more than willing to help.
as far as my knowledge goes, med schools do take into account extra time and any other extenuating circumstances/additional arrangements. again, someone correct me if im wrong