My new therapist thinks I have an Attachment Disorder. Limerence relates to this and also OCD.

Generations of women in my family have suffered obsessions with unrequited love! My grandma even had a Yiddish word for it, which I think she made up because I can’t find anything about that online.

For the OP on this thread, you have been given just a tiny bit of encouragement and feel hopeful from this tiny speck of what little interest he did show you. But, when you realize there is no hope that he has any interest in you, you will be able to get over this rejection and move on.