The truth is that we need to lean on someone from time to time. This guy thought you were sending him signals and has probably been interpreting your every move.

I would advice you to search your recent past and your heart. Did you maybe accidentally lead him on? If you did apologize and be honest. If you didn't then it is up to him to make it all better again.

If you were my sister, I would tell you that this guy is a jerk, for you to stay away from him and let me know if he runs his mouth, so I could shut it right up.

Even if you did flirt with him, he needs to take no for an answer. If you guys are pretty young still here is what probably happened from his viewpoint. He wants you, maybe he always did. Then you become single and since he 'fought for position' he feels he deserves a shot. He told his friends how he thought you actually might be into him because blablablayadiyadi and then he might even have gotten brave and told them he was going to make his move. Then he gets shut down and instead of realizing what's in your heart and owning up to his own feelings and the rejection he ran into, he gets angry and tells people his side of the story to reinforce his own perspective. A real man would have had a little conversation with you about this, let you know what he thought or felt if he felt the need and then respected your wishes and privacy. Also you would have been able to count on them still.

Worry about yourself and if anyone asks your answer should be along the lines of "Listen, I was just dumped, I am sad and then my good friend decides this is the moment he will destroy our relationship and give me a bad name in the process. That guy got hurt by his own damn design and now he's throwing mud at me for not fucking him simply because he felt entitled. Even though I was with someone else until recently. I honestly thought we were great friends and I counted on him being there in situations like this with no hidden motives."

Be honest.