a-level biology tips and more...

hey there,
you may have seen my post around but i now know what is going on. i take 3 a levels (psychology, sociology and religious studies) and started them in january this year. i didn't expect there to be this much content and i should have been better with my time management. i have done well though because im teaching myself and i do know a lot of the content but not enough for me to move onto year 13 in september. so, i had a chat with oxbridge home learning who i study with and they said i can take my exams in 2025 as well as adding another a-level (biology) as well as taking igcse biology but im going to study igcse physics & chemistry without oxbridge home learning as im sure its ok to self teach without them. im only trying to get 4s anyway for the sciences because i need them for diagnostic radiography at university.
i will be studying AQA biology and if anyone has any textbook recommendations please let me know as i didnt get the right ones to begin with for my other 3. so i need to be more prepared this time. i will also start my biology in august after my holiday so im ahead.
i also will be paying with exams and practicals so all of that is sorted. idk how the practicals work and when they should be done, so again, if anyone who has done a level bio, please let me know
also, is it really hard to do all these four a-levels? even though ive almost basically covered year 12 for my other 3 subjects and would probably finish the year 13 content in jan/feb time in 2024? so after i can revise and revise for them and then also just focus on biology and my igcses.
for diagnostic radiography where most of the entry requirements say gcse science is a requirement, do i need a combined science award or can i just do biology? im also happy to do physics as ik physics is in radiography and pribably would help me with the basics but i dont want to be overloaded with a levels. i also find sociology pretty easy personally, so it feels like im only taking 3 and a half a-levels but its just the fact that, im scared for biology but i need to do what i can and i really want to challenge myself.
has anyone got any textbooks for these igcses? what do you recommend?