Firstly I don't think you did anything wrong where you g/f ex b/f is concerned, no body owns anyone else nor do they have exclusive rights to them if they have a relationship and it ends then that's it its over, and going on the first post in this thread, you say that she had left the relationship with other b/f before you and she got together, so that's not wrong, she was a free agent so were you, just because we may have a relationship with a person, we don't then own them.
So don't beat yourself up over that, put it this way, if you buy a 2nd hand car then once its no longer the original owners car, then its yours, until you no longer have use for it, a rather odd way to put admittedly.
Still I hope you catch my drift?
I also think that maybe you're trying too hard with this person, you're wanting her to see you've made improvements on yourself, which is good, however, if you point these things out to her, she is less likely to be enthusiastic over them than if she noticed of her own accord. I feel maybe if you just made the changes and left it for her to notice them you might find its better than just telling her Ive done this or that, actions speak louder than words. Remember the old addage "talk is cheap" so I would say don't tell her show her.
She also maybe feeling overwhelmed by your way of being, perhaps you could try to lighten up and relax, this might help.
You seem to be making her the centre of your universe, that's not healthy you need some outside interests. Get some therapy, or professional advice, this would probably help you more than anything else.
