Maybe the guy was a bit shocked that you had romantic feelings for him, and is keeping his distance for a while to give himself a chance to sort it out in his head? He may have been happy with you two being 'just friends'. i know some guys who find it quite refreshing to be friends with a girl without the idea being there that it could lead to something more, and because you brought this up, he may now wonder if you could go back to being just mates, as he may find it awkward now to talk to you about girlfriends etc, as he knows your feelings. I think you did the right thing, i am a firm believer in being true to your feelings so well done for admitting them to him, at least now the ball is in his court.
On the other hand, as you say, he admitted once that he thought he was in love with you, so maybe he is worried that if you do get together, in case it all goes wrong it might ruin your friendship.
If i were you, i would leave off from texting him for a few days (if you can!) and see if he contacts you. If not, why don't you call him and speak to him about it rather doing it by text message. If he doesn't answer or return your calls, i would consider forgetting about him. You could also try to visit him or send him letter or email explaining your feelings?, but as i say, the ball is in his court and if he doesn't respond, maybe its time to move on. X X