Lying?

I relapsed on self harm again yesterday. I have been avoiding my momma because I know she'll be devasted. Last time I relasped she almost cried. I know she thinks I'm upset with her. But really I just know she's going to be upset with me. Everytime I relapse I tell myself I just won't tell her. It's not really lying as long as she doesn't ask. But then holding on to my blades in her house feels like lying. I promised I'd tell her the truth. But how am I supposed to keep dumping this in her lap and breaking her heart?