Everything was great, we love each other very much. She says we might break up just because she wants to live according to her mom's expectations. She says her mom brags about her, saying she is not dating unlike many other girls. So she says she loves me but we might break up what must I do?

There's nothing you can do. She's the one falling behind from her mothers expectations. Respect her decision, and if her senses finally find her, she may find you.