Why is my ex texting me after all this?

I had to break it off with him 5 days ago because he told me he wanted space. Would come back tell me he missed me and go on as normal. But if i asked about us he'd say he wasn't ready for a relationship, the demand of it. I waited for nearly a month for him to be sure about me. So I ended things and he didn't even TRY to change my mind.
So I deleted and blocked him off everything except iPhone and I get a message that night asking why i deleted him and i said i don't want things to drag on and he just said can't we be civil? I said that we could be but i dunno if ready to be to which he said alright. I haven't spoken to him since then…
Today I get a message from him saying "Are you alright? I'm worried about you. At least text me so I know you're alright" I took a nap&woke up to a call from him.

Now, I'm not a danger to myself. I'm fine. I haven't even cried about this situation. I admit I want him back, but I'm getting confused. One minute he wants space, the next minute he's worried…

Can someone maybe tell me why he's doing this? Also should I reply?

It seems like he hasn't found anyone new yet, take the things slow if he doesn't wanf to commit yet break up, there's nothing being not civil by not being in contact, no contact thing is necessary to move on