"I was so pleased to be seen I made him repeat it."

I'm not surprised you are confused by that last sentence. I suspect that as a direct result of crying (the incident in fifth grade) the author's face was blotchy, and perhaps her nose was red (can happen to anybody) and that's why the boy said she looked like a druggie.

To be honest, I don't know what a typical druggie looks like - not within my experience - but perhaps it involves having a blotchy face and a discoloured nose.

However, the author was just so relieved that someone had taken notice of her and spoken to her (even though she was not being paid a compliment), she asked the boy to repeat himself. No doubt to prolong the attention she was getting.

I doubt if the boy was being sarcastic, just open and honest. The author sounds as if in need of attention.

This sentence is from the book The Crying Book. I guess it is sarcasm to himself