Be calm and confident in yourself and what you think you can contribute to her life. In the time you've taken to improve yourself, hopefully you will have evidence of that change. If the cause of your breakup was that you did not have enough time for her, show that you've altered your work schedule and made time to volunteer or pick up that sailing hobby you've always dreamed about. That will show you're willing to make time for things that matter to you. See where I'm going with this?
At this point, any negative feelings or opinions your ex had have most likely dissipated. He’s forgotten about the bad times, about the fights, about what went wrong. Human beings have a tendency to idealize the past. So once you’re “past,” he will only remember the good stuff and the bad stuff will drift further into the recesses of his mind. And it won’t be long before he starts to wonder what you’re up to…

Use that time to really understand what happened. Dating coach, Lisa Shield, adds: "There's a lot of fear when we try to put ourselves out there after having our hearts broken. Many of us don't have a good enough understanding of what we did wrong in the past. So, how are we going to prevent it from happening again? If you can, talk to a dating coach or relationship expert who can guide you to that understanding. Because, if you don't make sense of the past, it's going to be really hard to move forward." 

Lee Baucom’s Save the Marriage package of materials is a good starting point, as is John Gottman’s book The Seven Principles for Making Marriage Work. Baucom does a great job in showing you how to get a different perspective on all aspects of your marriage (and even on perspectives themselves). Gottman describes the dynamic happily married couples have that keep the negative feelings they have for one another from overwhelming their positive feelings. The book includes short tests and exercises designed to help you understand that dynamic, and to get it for your marriage.
Or you can say something like: "You may not like it, but most of what I do now, I do it for you. You've made a better person. I understand what it means to care for someone now that I've been with you. I want to share that with you again, this time better. Because I can't deny that I still have feelings for you. I'd be lying to myself and lying to the world."
My boyfriend and I were together for almost 3 yrs our relationship was amazing u til I made the biggest mistake of my life by sleeping with someone else. Eventually my boyfriend found out and he gave me a chance to try and make him fall in love with me again. It seem to work for about 6 mo the we were doing very well but I had a car accident became very depressed and had severe anxiety I asked him for support a week later he told me he no longer felt the same way about. He said he really tried after I messed up but now he just wasn’t in love with me. I really live him and want to make things work out. Anyone have any advice?
Alright, lets say that I was trying to get an ex girlfriend back and I had made it this far into the step by step process I am outlining here. I took out a sheet of paper and wrote down what I thought our best couple experiences were together. For the sake of this page lets say that me and my ex had an experience where we were watching a football game outdoors and it was really cold. She was getting very cold so I offered her my jacket.
We also know that there are exceptions. There are relationships that probably should not stay together, such as those with physical violence, cruel and ongoing verbal abuse, extreme anger management issues, or long-term unaddressed substance abuse, for example. If you're in a situation like that, please eek the help of your local crisis management center.
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