It’s all opinions here, so I will add mine 
- The ELAT matters a lot, and you need to scramble if you are going to get registered in time. If you decide History is a better / truer fit, then it's the HAT. Philosophy only comes a joint subject: + Physics, + Politics & Economics, + Modern Languages, + Theology, and there is a Philosophy test. There is also Theology + Religion, which has no entry exam.
- Did you take English Lit at your current college? would that prof write you a glowing LoR? If not, why not?
- You say "Lit, History, Philosophy, and Religion are my passions.", but in UK terms they are more like interests. At Oxbridge, the people who make the final admissions decisions are the tutors who will be teaching you (not an AdComm) and they are very specific that they "want students who love our subject as much as we love do". That's one of the reasons that getting into a. joint subject (such as English + History) is harder than getting into one or the other: both sets of tutors have to want you enough to take you, and believe that you love their subject at least as much as you do the other subject. I get that the fields you talk about overlap- but the multidisciplinary approach is in straight conflict with "pursuing one of them deeply via the tutorial system" in the UK. Have you read the year-by-yeat detail on each of these courses? Pretty sure that you will find lots of interesting parts in each of them, but that taken as a whole some will appeal more than others. You study your subject with such intensity that it if you don't truly love it university becomes a long, hard slog.
Here is what Balliol sends to students about to come up to Oxford for English:
https://www.balliol.ox.ac.uk/admissions/undergraduate-admissions/english-reading-list
If you think that looks like a lot of prep work for the summer after high school, before you start university, just wait until you see the pace once you get there!
PS: “The reasoning for the 3 was a combination of senioritis setting in, and a slight effect of it being the teacher’s first year teaching AP English Lit— syllabus didn’t really prepare for the exam at all, none of the intended reading lists were followed”
Yeahhh…no to blaming the teacher, especially for a student operating at the level you claim, in a subject you say that you are “passionate” about. A proto-Oxbridge EngLit kid would have read enough of the book options on their own to do well, just b/c they love the subject and those books are on many lists of ‘great books’. In 2 of the 4 HS’s the Collegekids attended there was no “AP LIT” class- the school felt that their regular English class was adequate foundation for the AP- and it was.