Welcome to growing up. It's a very small minority of people that "actually know what they want to do"eng teacher lol
On that note, why are you set on going into eng?
Do you want to be primarily a teacher or teach English. I imagine that just finding a job as a teacher would be significantly easier than becoming an English teacher in the UK. Also, teaching the language class for native students comes with the most out of class work for the teacher. Grading isn't the interesting part of teaching and as an Eng teacher you'll have many a essay to grade, where another specialisation could get away with multiple choice.
Also, I rather imagine that there's a lot of competition for that spot and that English majors aren't that uncommon in well, England. While it's not not equivalent, as a chem grad. I can pretty much walk into any school I want here and get a job as a teacher, because very few chemists go into teaching here. Conversely, we have a bit of a surplus of humanities graduates that want to teach in schools and that became a rather difficult gig to get.
Hell, a CS graduate could probably just whistle that he wants to teach in a school and that he'd be fine with the pay and he'd probably have an inbox full of "Have you considered applying to... x" within the hour.