hello and welcome lawra, in answer to your question, I don't think there is a quick and effective way to bring down your hba1c, but please don't despair ! It takes time but its do-able. I agree with TW suggestion above re the carb counting course. When I discussed pregnancy with my team one of the first things they did was to sign me up to a DAFNE course - would this be an option for you? There's also a great resource / booklet on the diabetes UK website which outlines how to carb count - I found it very useful in the run up to the course. I can't re,ember what its called but if you have a look at the website Im sure you'll find it.
With my first pregnancy I went to the pre conception clinic for about 6 months. Like you, I was told that I needed to be below 6.5%, whats important to remember though is that they don't just want to see that you can achieve that, they want to make sure that you can maintain that as well over a few months. I went to clinic every 6 weeks where they did my hba1c and went over my BG diary. I also had to have my eyes and kidneys checked, as pregnancy hormones puts a lot of stress on these areas so they need to make sure everything is ok from the beginning.
The duration for the pre conception phase for my second (AND LAST !) pregnancy was a lot shorter, I had the same consultant the second time around so that probably helped as we knew each other - I think it was around 3 months or so .
I can understand that at this point in time, it may seem like a lot of work needs to be done before you can go off the contraception, but trust me, its better for you, and for the future pregnancy. All the hard work that you are putting in now will be worth it. I was really overwhelmed when I found out I was pregnant but I also felt reassured in that that the previous 6 months of prep essentially gave me an opportunity to get to grips with things . good luck and let us know how you get on. x