and told her i would change my attitude to let her do as she pleases
What does this exactly mean "DeepOnion?"
Were you trying to control her she had as friends or when she went out with them and wear?
If that's the case then you would do well to show her that you're willing to change by getting yourself some counseling so that you learn to trust and self-sooth when you're not getting your own way. Control issues need to be worked on. You just can't say "I'll change" and then do nothing to facilitate that change.
If you don't want to do counselling then the least you can do is search the internet for ways to help you with this (or any other obsessive actions/thoughts you had/have while with her).
Perhaps if she sees that you're actually doing something tangible to change, she may be able to trust that you'll not revert back to your old self. Even if she doesn't want to keep this relationship going and wants to break up after this 'trial period' do some self-improvement work for YOU because no matter who you are with, you're going to keep running into the same problem if you don't work toward change.
Remember this: If you break up for good it will hurt but you will get over that hurt in time. If you work towards being the best you that you can be, then that time will be cut short and you'll heal all that much faster so try your best not to be scared about that.
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion