First off, ignore what Ledos said. You can do plenty more than teaching with a history degree, and hell, perhaps you even want to be a teacher.
Unless you want to go into a specific vocation (eg law, dentistry, accountancy etc), then pick the course that you think you're going to enjoy the most and get the most from.
After A-Levels, a lot of uni courses look difficult when you look through your first-year course list, but everyone else on your course is going to be in the same boat and your lectures and tutors are there to help with the transition from school to uni. It may look daunting now, but by the time you're writing your third year dissertation, you'll be wishing you could go back to the "easy" days of year 1.
So yeah, take a course that interests you, but also make sure it's a sensible subject so your degree actually means something once you graduate. Recruiters look upon history degrees favourably because you'll learn how to form an argument and think analytically. And you obviously have something of an interest in the subject, or else you'd never have applied to take the course in the first place.
And if it really is too hard, you can always transfer courses at some point during your first year anyway.
Good luck!