I don't want to sound too harsh here or too insensitive, but I've been in your shoes and the same situation as you have. In the end of the day, if she truly loves you she would have stayed with you. She may love you, but she isn't in love with you anymore.
You are putting yourself in a horrid situation and you aren't able to see it. Actually it will hurt you less if you let go now then if you tried your luck. She IS going to find someone, and then the excitement of a new relationship is going to kick in. I mean why would she stay with you after 3 years when she could have any guys out there that is new and fresh.
There is a lot of difference between what many girls say and what they do. I trusted my ex, until I learned she cheated on me. She then told me she was going to wait for me to come back from a trip and she went with someone else. I was with her for 3 years.
Use your brain and don't use your feelings. Read all the threads and your situation is so similar with many other guys, "she is confused", "she doesn't know what she wants", "she only wants a break". We have all been there and we passed through the pain so that we can tell people like you not to do the same mistakes.