I honestly believe what your ex is searching for is for something to fill the void, the loneliness and the sadness inside of him. I bet he loved you and he may still love you, but his problem is his own. His problem was nothing you did or said. His problem is that he is insecure of himself and he cant accept who he is, and has no idea what he wants. He is missing something in himself and he uses relationships to fill that hole inside of him. Neither you nor any other woman will be able to fill this hole, only he can do that and he may need therapeutic help to do so.

You should not blame yourself for what he did to you. If you feel you put all you could into the relationship and got nothing back then there is nothing you can do. You did what you could do, you tried, you dealt with the uncertainty and the fishiness and got hurt in the end. There are better men out in the world and you deserve to have the strength to lift your chin up and carry on with the strength you have. You will find the man who treats you right and gives back the same effort you put in. In the mean time just work on yourself, your life, your health and your emotions. Always work on bettering yourself.