When you think you cannot live without her and you feel like your life is incomplete you may have a challenge on your hands. If you think you might want to get back with ex girlfriend, you need to make sure it’s worth it.
What was the reason for the break up in the first place? If it was your fault then look closely at what it was that you did. Was it due to your selfishness? This is something that might be hard to do. Look at the actions you took. Were they the results of a self-centered person? If so, then what has changed? What makes you so sure that you are done being self-centered? Is this desire to get back with ex girlfriend a result of self-centered thinking?
Before you try to get back with your ex girlfriend, you need to make sure that it is a mutually beneficial relationship or it has very little chance of succeeding. If it is just something to try and fill a void in your life and heart then it may not be the best for them. You may have to live with the consequences of your selfish actions. Don’t expect to get taken back with open arms. You just have to know that if it isn’t good for both of you, it might not have good or positive results.
If the reason that you broke up has more to do with her selfish actions, then why do you think that she has changed or will change? Look closely at her actions. If there is genuine remorse and a willingness to change, you might have a chance. You need to ask “is she just going to do this again?” If she has a pattern of acting out of selfishness in a way that is harmful to your relationship and to you then you probably don’t. If you have significant reason to believe that what she did isn’t going to repeat itself then maybe you should get back with ex girlfriend. You have to see that she is done looking out for only her self-interest and is more interested in something that is good for the both of you.
In either situation, whether it was because of your selfishness or hers, or even both, you need to fully believe that the both of you can act in the best interest of each other. You cannot expect this relationship to go far if either one of you is self-absorbed. If you truly believe that you both are done being self-centered and can really be focused on the relationship it may be a good thing to get back together with ex.