Hi Llovese,
He may still be dealing with the emotional repercussions of a previous relationship.
The constant staring over the course of the last 3 months may have been due to him wrestling with the idea of approaching you.
However, he may have never approached you or started a conversation because he knew that he just wasn’t emotionally ready to do so.
He is probably still in that state of mind.
This may be why he reacted to you in an abrupt and angry tone when he turned you down.