Without knowing your story, I think he is moving on and he is wishing you the best in your journey.
I don't know that he is closing the door forever (again, not having any history) but it seems clear to me that although he misses you, there is too much right now to work through.
I don't feel he is not taking repsonsibilty for his part. I think he is just pointing out an area he doesn't agree with you on.
I wouldn't hang your hat on getting back together. Focus on learning how to live with your bi-polar because if you can't do that, no R will last.
Hang in there...
Serenity CL making a second marriage work
I don't understand someone looking for "closure". That's just a word, and it means absolutely nothing! Your "closure" was when you ended the relationship. Over! Done! Nothing more to be said! You're aware that YOU have problems. That's not saying he is or was perfect, but you were the one who ended it.
I see nothing confusing about his response. He pointed out that he'd "tried". He suggested that you DO have a self image problem, along with the possibility of other problems, and opined that you should continue with your therapy.
The fact that he said he "misses you and thinks of you daily".......was a kind way of ending the reply. He COULD have said many other things, mean things, but he tried to end it nicely. I miss several people that had been important in my life over the years, but I wouldn't get back with them ever, for any reason. And like him, I remember the good times with those people, knowing full well there were more BAD times, which is why they're no longer in my life! When someone is driving you up a wall, you try to think of why they would do it......which explains his "backseat" diagnosis......and there are plenty of professionals who also mis-diagnose mental and emotional problems. YOU ended the relationship, he didn't. Anyone with mood swings is possibly bi-polar, but no matter if that's correct or not, it's difficult and sometimes impossible to deal with a person like that. You need to stop worrying about hidden meanings and get on with your therapy. And good luck with that!