im sorry but i think you are being weak. we all grieve for a period when a relationship ends but it mustn't overwhelm your whole life forever, after the period of grieving you have to move on and get on with life.
you have to learn to be happy with life on your own first, you don't need anyone else to make you happy, at the end of the day you are the one who is now missing out on life, not him.
immerse yourself in your career, or a hobby, do things that make you feel good and take your mind off things, go out with your friends or family and resist mentioning him all night, tell them your now feeling great, lock all your old photos of him and the two of you away in the attic, hate him rather than miss him if that helps you move on.
rem, life is too short and it flies by at a frightening rate, you need to get back on track and enjoy it.
good luck