Its hard to relapse after a lng period of time i completely understand i havent in two years and found myself last month going back to cutting. No one is perfect and there will be days when you mess up dnt be so hard on yourself thats what i and is still learning to do. As far as your new friends you dnt have to tell them anything unless you want to. If you feel as of they will hate you and not be your friend anymore because you cut yourself then they were not true friends to begin with. They may have to be educated on this topic to probably understand it if they dnt know already. But like i said you dnt have to rush into telling them. n stay strong! Remember your not alone and everyone struggles and slips up including myself