I cheated on a maths test and I feel so guilty?

I cheated on a maths test and i haven't been able to stop panicing all weekend, i can't stop crying. I feel so sick inside and terrified. I wish I had never done it but I don't know what to do. I don't want to tell the teacher as I may get in trouble but I am scared she might be able to tell from my answers that I copied. What do I do, please reure me I am on the brink of hurting myself here. I prayed to god and asked for forgivness but I still don't know what to do. I am petrified to go back into cl tomorrow.