I want my ex girlfriend to take me back, but I have an addiction problem?

Your addiction makes you a danger to yourself and anyone whom you are in contact with. That is the harsh reality of it. You could not possibly come through in a crisis for example if you are stoned and your infant child needed you. Your priority right now needs to be on getting well. You need professional medical help to get well for sure. But to ask her to take you back right now is unfair. Seek support of a local detox center and consider going to treatment. Due to your drug of choice detoxing on your own would be dangerous and could be life threatening. In the end, you need to do this for yourself. Then, you have something to offer to those you love. Financial obligations, depression, being away from those you love and handling feelings of loneliness and rejection make facing sobriety a daunting prospect. But, you need to take these aspects of reality face on in order to begin to resolve them. Many of us out there have started the recovery journey. It is possible. I have been sober now for 10 1/2 years. At the beginning my life was such a mess I hardly saw a way out of it all. But to begin is the key.