If it is true that he feels the need to "celebrate" your engagement and has to wait for the right time, he will be waiting for a long while. There is no perfect time to be engaged or married. People do both knowing that nothing will be perfect. You are right that no one would let their partner feel so upset. He should be putting you first and he is not doing that at all. He is putting himself first. There is no real way to find out why he is doing this except by seeing his behavior for what it is. He is telling you how he feels by how he acts. He probably doesn't know why he does these things himself and may not care. He seems interested in what he needs and that is all. He certainly has feelings for you but whether or not they are healthy it is hard to tell. You can only do what you need to do in this relationship. And right now, he is causing you pain. And your relationship is very unbalanced, and not in your favor. It is up to you to decide if you are willing to continue as things are or back off for a while to see what happens. Kate
I think your feelings about him are accurate, as painful as that is. And I know it's not an easy thing to face. But his behavior has pointed to exactly what you have described. He is probably using you and your abilities to make him look better and hold things together. Otherwise, he would commit to your relationship.
You might want to take some time to think through what you want to say to him. Decide how you want to say it's over. List the reasons why and read them then re read them so you know what you want to say. The less emotion you use, the better. Stick to the facts and keep to the point. Something like, "I am not happy in the relationship and think it is time for me to move on". Then if he asks why, bring up the reasons you listed. After you have talked it out, leave. Don't contact him and don't speak with him. That way, you can have the chance to heal.