Why did I just do that

I'm an adult man. I have a mortgage. I have a wife. Fucks sake I've got children. Why did I just do this after they all went to bed?

I've never done this before. I just felt like such a bad person tonight because she told me I only think about myself. I thought I didn't because of how much I work for all of them. I rebuilt a house from the ground up for her. But if it's what she sees from the outside then maybe it's true. Maybe I'm just a parasite.

What's she going to do to me when she sees these marks? What can I tell her it is instead? I'm really trying not to bleed on the couch, it'll never come out and she'll never forgive me. I think she'll leave me if she finds out what I just did.