I ruined everything

I messed up. Really badly. I went to meet my partners brother and sister in law and accidentally said somethings that I shouldn’t have. I made it seem like he was talking behind their back and his sister in law was really upset by what I said. We spent 6 hours and fought the entire time. He said he will never forgive me and doesn’t trust me. I don’t blame him. I broke his trust and really hurt him. I can’t forgive myself for hurting him like that. I tried to walk away but he won’t let me. How can I stay with someone I’ve hurt so bad that he won’t ever forgive me. I feel like I need to punish myself. I really hate myself so much right now.