Being Honest

I've been seeing my boyfriend for 8 months. I recently had a fight with him and ended up going out and hooking up with another guy. We didn't have sex but it got close. I know I made a HUGE mistake. I felt terrible after it. I told my boyfriend after we made up and he can't get over it. I am SO SORRY and it was a mistake and I want to make it work. It was stupid and now I'm going to be alone for the holidays because he said he needs time. I don't want to lose him but I think I might. I'm asking for his forgiveness and I need to know if I deserve it.