the best way to deal with it is acceptance. if you can't accept the one year anniversary, you'll never be able to face the next 75 anniversaries. diabetes is now a part of you. no matter how much you hate it, ignore it, wish it wasn't there, pretend it doesn't exist... it will always be there. embrace it - don't let it control you. you have the power to be in complete control of your own diabetes. it will be scary and frustrating at times, but this is something you can do. stand up, take control, face it.
i've had diabetes for over 20 years - my anniversaries are just another day. i don't do anything special. if you know it's going to be on your mind all day, either make plans to keep yourself distracted or meet it in full force and throw a party. there are lots of people on here who celebrate their anniversaries. it is life changing - you can do with it what you want, just don't let fear take you over.