I don't know what to do, plz help me out!?

Given that despite your mum's advice, you ask this here, I think your decision is sort of clear already: give her another chance, she really seems to be regretting what she did, and I think that you would be able to sort this between the two of you. Seeing that you were crying over her, you quite clearly love her, and this is a chance of proving to her just how much you really love her: she clearly sees that she's made a huge mistake, but if you can forgive her that, then you can truly say you hav done everything to keep your relationship alive. I've once been in the same situation, but i told my ex to go to hell, and I regretted it for years, so don't make the same mistake. And after all, we all deserve a second chance. Hope that helped, and that it will work out between the two of you :)