why do I feel bad about not being noticed by my teacher

This happened a few days ago with my math teacher

some context first:

My math teacher is very attractive to me (and I'm only saying this because it applies to the story) and I share this taste with a classmate of mine that i'll be calling Sarah. Sarah and I thirst over him in basically every class (of course needless to say that it's not totally serious because both of us have partners) and he has a special liking to her simply because she's the best in class and she's more interested in math than anyone else.

At the start of the year he also laid his eyes on me cuz tbh, I'm also good at math without any effort, but that's the problem... I put no effort in it and sometimes I even end up failing exams...

I guess this has made him stop liking me or smth like that cuz he's just lost hope in that I will try to get better grades... Idk why but that fact made me really sad because I felt like I was dissappointing him!!!

Anyways, the other day I got up from my seat to speak to another classmate about a math problem we were doing to see if he had the answer and the teacher sat in my seat next to Sarah and spoke to her for quite a while.

After class ended she went towards me kind of shocked and told me that the teacher told her that he was worried because he had seen she lost some weight and wondered if it was an ed.

For some reason, that irked me... The exact reason I don't know but it probably has to do with wanting attention from older men cuz daddy issues lol, but it really bothered me that I had been actually going thru hell and even with stuff like eds (btw she's fine and she just has a high metabolism but she is underweight) and I somehow never get noticed about it, no one asks if I'm ok... I thought that maybe I should show it more, hurt myself further... Ofc these were just thoughts and I wont be doing that so some random guy notices me but it made me realize... damn... Maybe I do have issues...

not really more to say about it :P