I’m failing

I fell in love with my fiancé over two years ago, this morning he ended our relationship because he wants to know who he is. He said he lost his spark in our relationship. I told him I’m not ready for our relationship to end and that we need to talk it out, after 2 hours of talking I came up empty handed as I asked him why he fell in love with me so many years ago and he said he doesn’t remember, the thought of it is there but he can’t remember. How to I “re-spark” our relationship? He won’t give me kisses, hold my hand, tell me he loves me or anything. Last night all was well and perfect or so I thought. He is/has been my only boyfriend and my first for everything. How do I fix it? He didn’t break up with me for anyone else, or to start talking to someone else and he wants to remain best friends, but I can’t give up yet. How do I fix it?

UPDATE:

We talked some more and decided to try to work it out. He’s stressed and overworked, we’re planning to go away far from town this weekend and have some much needed alone time. We live with his parents and he thinks that’s also a problem that he’s having with our relationship right now. Over two years is just too much for the both of us to throw away we decided.