I'm in my first year of sixth form, and it's great, but I get what you mean when you say it becomes a bit of a drag. We recently had a day off dedicated to university stuff - lectures etc. about different universities and what it's like there. Me and all my mates were going on about how awesome it sounds, and we genuinely can't wait to go.
I plan on dropping art next year, so that'll free up a lot of my time for my other subjects. (I say this, but I'm probably just gonna spend all my free periods playing pool :P) For you, you've only got a year left, so work hard and hopefully you'll get your desired grades and university of choice.