He just went NO FEELINGS?!

Okay so, I have written with this guy in awhile, and it really felt like we actually could build up something more. We planned to meet and everything, but all of sudden he just wrote:

“I don’t have the same kind of feelings anymore, so I think it’s the best if we stop write to each other before someone gets hurt. You’re r really nice”

And I’m like “excuse me I actually started to like you and now you just gonna walk away?😦” But I didn’t send that obviously...

I have no idea what I should write back, so I thought that you guys might know something. Should I just go chill and say “Okay I understand...” or should I get

angry? But if I get angry he might hate me and I still like him, so maybe I could ask him to still be friends or something...

Please help because something like this has never happened to me before. And I have no idea what to do...