I would repeat the AS's you think you can get up - sometimes you just need a run at it first to get the hang of it. Homeschooling as well will have made exam technique harder!
I wasn't homeschooled but I went from a low B in biology to an A* by repeating only one AS module, it's very doable! I found revising AS material also made the A2 easier to understand. If you repeat, focus on exam technique more - you can know and understand everything but if you don't hit markscheme like they want it's harder to get marks!
AS's matter to unis if you take them onto A2 (as they count towards the full A-level).