My gf just dumped me after i asked her to marry me

So I'm 24 M, she's 23 F. We've been together for almost 7 years, and I asked her to marry me on Saturday, and she said yes. But she said that after i asked her, she went home and thought about it. And today, i told her that i was going to ask my mom to live together, and she said that no, we would live in her house, and i argued that we can't live in her house, so i can live on my own, and she suddenly said "fine, if you want, we can break up". I was shocked, and i said "what? No, we are going to marry" and she said that she doesn't want to get married anymore, and that she doesn't want to live together, and i asked her why, and she said she doesn't want to, and that's it. We've been together for 7 years, and she was so happy and smiling just a day ago, and now she doesn't want to marry me and live with me, and i feel like a huge failure, i don't know what to do, i feel like i lost my whole world. What should i do now?