pink.. try to let go of your past.. i do also thinking of my ex. but when you have a new start,you must forget about everything that you and your ex in that past..if not the relationship with this new one will not be lasting.
You still feel that you love him because you have not let go of him. You need to let yourself move on otherwise you will always be living in the past. He broke your heart and it has been four years I think it is best that you forget about him. Get rid of anything that reminds you of him.
You really don't love your ex, you love the idea of your ex. I am sure you had good times, but you broke up for a reason. Some part of you will always care for him, but it is time to put that behind you and move on. You may also be using the feeling to prevent you from committing to someone else. You may be afraid to be hurt again.