Why the petulance? Goodness, stop embarasing yourself: She's asked you not to contact her and give her space and even in your giving her of her space, you have to do some banal, immature thing that will cement in her mind even further that she's done the right thing in backing away from you and (what appears to be) your immaturity.
Sorry to spill it out but you've shown us here, in a few sentences, in how you've handled yourself that email she sent you was warranted.
"I'll post back all her old birthday and x-mas presents" Don't bother. She didn't asked you to do that and she will only dislike being in your life even more if you carry through with your "threat."
Focus less on her and put it where it should be ~ On your current gf. Get yourself some male friends (or focus on the one's you currently have) and quit being any chicks MALE GIRLFRIEND.
Last edited by Wakeup; 20-11-13 at 05:50 AM.
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion