I cried when my girlfriend said goodbye?

Since you cried, it means that you don't want to break up in your heart, or that you want to keep this relationship. After all, this is your first love, and it is often the most emotional and difficult to give up. So obviously you are particularly reluctant to give up, but since you lied to her, you have to make amends. If you want to continue not to break up, you should try your best to compensate your mistakes and minimize the damage. Actually, I think you should ask her out. Tell her your love and let her know your heart. Only in this way can she accept you again, trust you, stop alienating you and continue to love you again.