The idea that someone likes me but still can't forget his ex is eating me alive

Recently I came to know that a guy from my class has a liking on me. My friend noted that and confronted me about it. I refused to accept it but at the same time my inner self was so relaxed and happy I just can't explain. It was because I too got a liking on him but never accepted this to myself because of the fear of abandonment and rejection. It seems like that fears are back to haunt me down. The thing is, yesterday when I was in my valorent match my roommates said that she would tell me something if I put my mic on mute, So did I. Then she just dropped a bomb. She said that that guy couldn't propose me because he couldn't forget his ex whom he dated for 4 years. I was like, WTH!! Was he treating me like an option? I just couldn't understand this. And now this is eating me. I asked my roommate about this again and she said that it was a joke by the boys. But I couldn't see the truth in her eye. I am feeling betrayed. Why he was trying to drop hints when he couldn't even forget his past and move on. Why he had to toy with my emotions. Who gave permission to do that. I am just broke. Worst of all I am feeling guilty for allowing myself to fall for him, fall for the gestures which were not even true. I don't understand why its always me?