What do you mean when a girl sends a message to a boy and doesn't reply?

But you can guess that the content should be unusual, otherwise you wouldn't be so upset.

Either he didn't receive it for some reason, which belongs to the idea of comforting you.

Either he is avoiding you, if so, you should know what this means.

You can make a tentative joke and ask him why he hasn't returned your text messages. Don't be accountable, because after all, things haven't been clarified. Don't screw things up on impulse.