Dropped without an explanation

What do you do when someone who said they loved you and wants a future with you, just drops you without an explanation? Without a reason? How am I suppose to handle this, I feel like my self esteem is so much lower now because I didn’t even deserve that. It would be different if we broke up for an actual reason that makes sense, it would be easier for me to move on that way. I get it, people don’t work out, that’s life.

But to say he loves me and wants a future with me and then to just stop out of nowhere... it feels like it’s much harder to move on in this situation because it left me with so many questions, and wondering why I wasn’t good enough.