A friend of mine recently achieved DDDE for his AS, and he really did strive to do Medicine at University.
So he bloody did well work hard from day to day for the remaining year at school (where he did his A2s, along with his AS work from the year before), and turned it into something like AAAB at A2.
Folks here are just saying it's unrealistic because the university won't actually know what you're capable of, as they haven't been your teacher before. However if you mention it that you're going to retake some exams or something like that, because you didn't think you performed to your absolute best the first time, and you persuade your teachers that you're absolutely going to stomp on your exams come next year (providing you do resits), then go ahead and get them to predict you what you're realistically capable of.
As you said, you're applying to Medicine this year, go ahead and definitely apply. It doesn't matter if you get 5 rejections, you can always apply again the year after with your achieved grades, and thus you'll know where you're capable of getting a place of and such. This'd probably be the better idea, and the more viable route to go down!
I also got ABBC this year, wanting to do Medicine, and this is basically all the information i've had from everyone I've spoken to.
Edit: Didn't see the part where you said about exceeding your grades with your results next year. If this is the case and you feel that this will happen, it'll be better to apply next cycle when you actually know your grades. Nothing wrong with a gap year!