1.) It is vital that you get over the panic and stress about your breakup. You cannot take control and actually do something that will work when you're stressed out. Don't discuss with your friends all the wrongs that your ex did.
This type of discussion only serves to strengthen negative feelings. Talk of this sort will make your friends feel uncomfortable. Their suggestions will be of questionable value if they're inexperienced at dealing with relationship problems.
2.) This problem isn't going to repair itself. You will have to put forth the effort to change things for the better. A cool head will be needed to do this.
After your breakup, your first impulse will be to try to fix things up as quickly as possible before it is too late. Relationship repair cannot be achieved overnight. In fact, it's best to allow a cooling off period of about a month.
It's also good if the breakup happened in a mature and non threatening way. Time is required to reflect and to get things into perspective. It's important to understand the reasons behind the breakup before you try to contact her.
3.) Establish a friendship with her. This may be somewhat difficult but it is well worth the effort since it allows for further contact with her. The current status of your relationship is always defined by what was said during the last contact. Her present thoughts about you were molded by that last contact you had with her.
Do some of the fun activities you did together before you had sex. This will bring out her memories of the good times of your relationship. This fun aspect of your past relationship will make it harder for her to leave.
4.) Be very careful when drinking alcohol. It will distort your common sense and judgement. The consumption of alcohol late at night often causes a person to give their ex a phone call.
No one is in a good frame of mind when they're wakened late at night by a phone call. This is doubly so if that call is from their ex. On top of this, the alcohol will diminish your inhibitions and you will regress to the usual behaviors that causes conflict.
5.) Get out and have fun. I know that it's easier said than done, but it has great therapeutic value. This is the time to renew the old friendships and make a few new ones. Living life again will give you a more balanced perspective and help lessen the pain of separation.