Dude im also in a bad boat here!

last week Tuesday i take my girlfriend out !things get heated and we went to my place'
The next day she sends me a text that shes dating a new guy !
So i wished he good luck and said i needed a break to be single and free awhile actually although i was hurting inside.
She texts me 2 days later saying shes lonely and that i must come visit..i agree to come and ten minutes later she replays rather not she tired .
Its funny shes only known this guy 2 weeks and only knew his real name 4 days before they started dating
Iv started no contact with her but id like to know what is she trying to do and how i can make her run after me?