Hi Kieron, can't add anything too new to what's already been said but I'd certainly advise you to do two things.
1. Forget the past and start now, great time being the new year and all, and take control.
2. Don't get too bogged down straight away with carb counting - speak to your Diabetic team and start as though you've just been diagnosed. For me, that meant keeping a log of my readings, having set doses of insulin and speaking to the diabetic nurse every day for a couple of weeks to adjust doses and get things stabilised. Use your diabetic team!! It was approx. 4mths before I started carb counting and by then I had the basic tools to adjust doses based on readings alone. It helped enormously. Regular testing is the most fundamental thing you need to do, it will arm you with the knowledge you and your diabetic team need,
But seriously, wipe the slate clean and start again with a serious and motivated mindset. You will get it under control and you will eventually wonder what you were so worried about. Keep posting and keep us informed, whether good or bad, you will always get sound advise and support.