I know it isn't easy but perhaps it is for the best. You've lost someone you hold dear by calling it off. You've tried your best to break it gently but it seems there is no other way. You gave him hints but he didn't seem to connect the dots. You tried and that's what matters. After all, there is no sugarcoating rejection. No matter what form it takes, it would always hurt .
He might say that he is the only one hurting but he will never know that it pained you, too. Who ever said it was easy? No stuff involving emotions has ever been simple. It's a two-way process. Every decision, even how small it might seem to be, affects the whole.
Don't say you're sorry. You did what you had to do. Yes, it might hurt but then again, ignoring the reality would only make it worse. Give him time. Give him space. Let him heal. Allow him to find himself again. Let him find all his broken pieces and fix whatever he has left. As for you, do the same. Remember that life goes on. I cannot promise you things would get back as they once were but I can assure you that you would find the answer. Maybe not now, not soon, but eventually you will.
For now, let the world spin. Go with its flow. Hurl yourself to a whole new perspective. Everything will get better in time. Yes, in time.