Most Helpful Guy
Be his best friend. Talk to him and listen to him. He will appreciate that you're there for him. It's going to take time. Trust me. Tell him you care about him but don't say you like him. It won't help yet. Tell him that he deserves better and there's still a lot of people that care about him including you. Give him a big hug when he's sad and pay attention to the vibes created. Maybe even a kiss on the cheek at the end of the hug and tell him you're there for him. If he has any romantic interest for you he will sence the vibe and give him something to think about. It won't be coming on too strong and if nothing happens you have nothing to be embarrassed about because you were there for him as a friend.
Most Helpful Girl
it's hurt my heart to read your story, how a guy didn't even sees there's a really caring girl near him and always there for him. it's okay, just let him be happy, try to ask him to hang out and do fun thing, to make him forget about the pain, and yes, hope that he'll see you. be supportive and give a true advice, it helps him to move on. good luck