I think as soon as you find yourself thinking about him in a negative, cyclical sense say to yourself 'stop,' and remember all the ways in which your life is better off without him in it - physically write it down if this helps reaffirm the process. Keep that piece of paper, refer to it or put it in a place you can see it often. I don't think you've wasted years being with him - we can always obtain something from relationships and at least now you have a better idea of what you want both from a partner and the relationship you share. Perhaps write at the bottom of your list or whatever; 'i'm free now to be with someone who will love me and whom deserves my love.' It sounds really basic and probably a bit dime store philosophy but i think just having gentle reminders like these are important - a lot of what we're influenced by is external. I think this is why something tactile, something you can see and touch is important in that respect. In time you will see the positive sides of your experience more clearly and any hurt caused by being with your ex won't be so painful. Time is a wonderful gift in that way. Right now it's about letting yourself grieve for the end of something that was meaningful and important to you. Be kind but firm towards your feelings, most are there as a way to help you heal but the possessive, controlling thoughts can be dealt with if handled in the right way. I hope i've been of some use. All the best.