First of all, let me just say that I am SO sorry for you. I know I can't change the situation for you, but I just feel so damn awful for you. I've been in the same shoes as you, and I know how raw and horrible it is to be forced to say goodbye to someone that you would do ANYTHING for.
So in answer to your question, there really is no set time for you to get over this girl. It takes as long as you need to get over her. It's all down to your mindset and your emotions. I can tell by your words that you feel really hurt, and that you loved her very much.
You now have to go through the 5 phases of losing someone.
1. Anger- You may feel resentment towards her, like she's done something really wrong and you are really pissed off.
2. Sadness- You're gonna miss her like crazy, you're gonna want the closeness, you miss the kisses, the hugs, the words of affection. I know how hard this one is hun.
3. Denial- You think that you will get back together. You pretend that everything will be fine to try and convince yourself that you still have her. Maybe this explains why you bought those books?
4. Depression- You feel so sad, like no matter what you do, nothing is gonna make you feel better. For a while you'll see no point in things, as if if you cant have her, you don't want anything else.
5. Acceptance- The final stage, you'll come to terms with your loss and you'll try as hard as you can to move on. This doesnt mean you wont love her, it means you will understand that you need to let her go and find someone else.
These stages dont necessarily go in that order, and you may revisit some of the stages before you get to the acceptance stage.
I know that right now you are feeling vulnerable and exposed, but you can get through this. Now you need to get rid of those books and try to understand that you guys are done, and that no book can make someone fall in love with you again.
I'm sorry that you're hurting.
xx