On a serious note - I think you need to give yourself some self-worth. If you slept in your lessons then no wonder you came out with bad grades. My friend (who sat next to me) in Lit slept when we were doing all the exam prep for Section B Poetry stuff and guess what? He managed to SCRAPE an E for his exam grade. By scrape, I mean one mark down it would have been a U... Which goes to show you have got to pay attention in class!
I know I sometimes didn't in my classes so I would use somebody's book to copy notes and go over them in my free period. I was watching Everybody Hates Chris and Chris got an F in his Math test and you know what his mum said (paraphrase): Chris, I know you're not stupid so don't act like it.' -lesson learned.
You claim to be 'naturally intelligent' but last year, you didn't use that intelligence to help you? So if you are not 'dumb' then don't act like it. It's honourable that you've owned up and took responsibility for your actions. Now you're facing the consequences, which is also good. Now you need to learn from your mistake. Motivation will not come looking for you. You have to find it yourself which I thought was a challenge. But you've got to find something to motivate you, something you want to aspire from! Also, as soon as possible find a revision technique that helps you!
I have a friend who failed his AS he got CDUU because he just couldn't bothered (like yourself) and this year he got DDU too (even though he claims he revised and etc, which I know he didn't because he decided to go football 20 times a week, play at the casino and work crazy-ass hours). You need to dedicate your academics with your pleasures and prioritize your time management. On the other hand, you might want to think about many A-levels aren't for you? If you literally said you found your A-levels boring then honestly, most likely you will find all of A-levels boring and God only knows what you are going to be like when you come to revision (if you get to that stage).
Bottom line is, if you claim to be intelligent then prove yourself right and get the grades you want to. No point sitting there saying "I'm so smart" then not having the evidence to back up that claim.