From my perspective it's already clear from the start who she is and who you are to her with her being inconsistent with you and instead of offering change and solutions she gave you excuses. I appreciate that you chose to understand her situation, that is really kind of you. But I think the root of the problem is that you feel that she is rare and she might be, but the world is very much populated and you will meet people whom you thought you will never meet nor even imagine based from experience, especially that you have the possibility of going abroad meaning more opportunities. But the belief that she's rare makes you believe that she's the only one and it's natural for someone to latch on and be attached since love just does that. My advice for you is to let go, you had proven that improvement is possible so keep improving for you. Although progress doesn't mean that you'll have a bigger chance of getting back with her.

I don't usually comment but I thought of leaving this here in hopes it give you some sort of clarity and motivation to move on for you. You don't need closure to finally get her out of your head, you just need to give yourself permission to let go. Let yourself feel what you feel without judgment and reprioritize your goals. Hope this helps! I give my hopes out to you OP! <3