"How do I get back with my ex girlfriend"? Let me tell you this: The simple fact that you are asking this question and looking for its answer in the Internet makes you closer to your girlfriend.
Why have I said that? Because from personal experience I know it full well that if you try to answer the question "how do I get back with my ex girlfriend" by YOURSELF, the answer will be something totally nonsense.
It's a great thing you are reading stuff over the internet to get your ex back.
When my girl left me, I thought the world ended.
I loved her so much, and I was utterly devastated by the thought of having a future without her.
Just thinking of the good moments we had together was unbearable for me and really - those days are like a bad, bad dream right now.
What I did wrongly was simple - I followed my own wrong thoughts about how to get her back to me.
In such a devastated state of mind, was it really possible that I would be able to produce some genius method to get her back into my arms? No.
But I followed my own ideas anyway.
What were those "ideas"?  Call her, beg her, terrorize her with text messages, shower her with gifts...
 These are fundamentally wrong because begging will never really get you anywhere as far as relationships are concerned.
 And even if it did make you get your ex girlfriend back, how healthy would that new relationship be? As soon as I quit following my own nonsense "plans" and looked for outside advice, which is what you are doing right now, I was able to come across some really cool methods.