I've told a lot of lies. But the one that comes to mind right now, is when I lied about cutting.
My grandmother had caught me one time, and so she had these regular checks (embarrassing, but necessary).
Soon, she slowly trusted me enough to stop checking and just asked me if I was doing okay. I did good for a while, honest. But then I relapsed, and when she asked..I lied.
What made this so awful was that she found out. And she didn't trust me. Probably won't ever trust me again. If you self harm, please get help. Lying to others and yourself won't change anything.