It happens to us all on diagnosis I'd say. Sorry you are feeling so depressed. It probably won't help you now but try to remember it isn't the end of your life, diabetes is manageable and it shouldn't stop you doing anything - well apart from eating lots of cakes and sweet stuff
Spend some time around the forum, I quickly realised that I could cope with this, I could enjoy my life still - drink red wine, eat cheese, feel healthier and manage my condition. But I also remember how devastated I was so take so time for yourself, read about the condition and then you may feel calmer.
Best of luck, please remember you are not alone.