Most Helpful Girl
Just move on. That is way too much drama for a girl when you could be with another girl who doesn't mess you around like this.
Most Helpful Guy
She's not ready for commitment, and even worse, even if she was, she still wouldn't see a future with you, as you said at the end.
If you want a stable relationship, your best bet is to drop this girl at this point. I think your girlfriend is suffering somewhat from a phenomenon called "GIGS", which is very normal. Look it up. "Grass-Is-Greener Syndrome". Very common for relationships under 25, which is why marriages have a significantly less chance of working if the two involved got married before one of them was 25 years old, statistically. And this is why dating under 25 seems to be the most sporadic and all over the place with a lot of drama. The prefrontal cortex is still not developed fully.
The best attitude to have is a) avoid scarcity (check out myTake: www.girlsaskguys.com/.../a22231-scarcity-fundamental-setback-in-dating) and b) go into every relationship with a, "Hope for the best; prepare for the worst," attitude and basically don't be too concerned about the outcome, and just enjoy them while they last rather than having a lot of expectations.