@yoyo100,
yoyo100 wrote: He only likes me as a friend. I've told him a lot of times that I have feelings for him, but he tells me that he is still in love with his exgirlfriend.
I think you're very lucky that he has been so honest with you.
He's giving you the message that he is not interested in you. He is giving you the opportunity to find someone who is interested in you - and to not waste time on him.
If you really value you him as a friend, take the information he has given you and use it. Ignoring what he has told you is not just rude, but it's inconsiderate of him and his wishes.
Continuing to tell him you are interested in him, after he's indicated he is not interested in you is not nice.
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He could be talking about his ex-girlfriend to get you to leave him alone. It seems like you've been pushy and overly self-involved in this. Perhaps it's immaturity, perhaps it's a pathology of some sort, but it's not nice for the person on the receiving end of this sort of behaviour.
Think about his wishes. Whether or not he has someone else, he doesn't want you.
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How do you move on from this sort of obsession? You start by not posting about him/talking about him/bothering him. You also open yourself up to the idea of talking to other men, having coffee with them, being receptive to their conversations, smiling at them in elevators.