Okay, I think you might need to consider dropping one of your A-Levels. By dropping one A-Level, you can lighten up your workload. If you stay at 6th form, you might have opportunities to do DOE or go abroad to another country, which will look good on your translator CV, especially if it's a Spanish/French speaking country.
You don't necessarily have to go to uni. You could take a gap year, teaching children how to speak English or find an internship/job in translation.