Let it GO. I know it will seem hard, but in the long-term it will be the best. If he is being open and honest with you about his feelings, leave it there.

I just got out of a ‘forced’ relationship (well, great at first, but forced after about 6 months) and I can tell you that even if he did agree, it could work (maybe), but could lead to anger, frustration, and insecurity.

Be glad he is being honest with you, and respect his feelings. Only if he brings up getting together again would I consider starting a relationship. Don’t pressure him, or nag him. Let it go, and if it is meant to be it’ll happen. If not, another person is out there that will be right for you.
Hope this helps!