Ok, despite him being a seemingly good guy I will advice you to break up with him anyway.
You have tried for a LONG time already. It is very well possible that you do not understand your own emotions and need professional help... so I will advice you to pursue that. However, at this time, while not knowing what exactly you feel and why you feel that way, having him in your life as a romantic love doesn't seem sensible.
Break up with him. Let him know you need to sort yourself out on your own without expectations. Perhaps you'll feel you miss him eventually and want to be with him again, but for now you need a long break from him and professional help.