I started a new job this week, while still having depression, and I despise it. Since I'm a person who is always bored and hates it the first weeks, I thought I'll just give it time but some stuff happened today that hurt me and I don't know if I am misinterpreting it and should quit. 

There are girls my age in the office, one of them is "responsible" for me since I'm still a student. The first days they always called me to lunch together with them in the work cafeteria. I thought they liked me cause we had similarities. 

Today while I was doing tasks with a cool, introverted girl in the archive room, she explained me stuff really good even though she was also new and another coworker came in and told us in an arrogant tone "are you guys finished?" and told the girl that explaining me stuff isn't her job but the other ones. I was really shocked because it was such a degrading tone for both of us and mean.

After some work, the girl responsible to me, came to me and asked if I am going to lunch. And since I'm shy, it takes courage for me to ask other people stuff like "if it's okay, I would like to come with you guys too" but I did it. She said she's going with the others to a restaurant that requires a covid certificate (that I don't have) so basically I was left alone. I'm used to that but it still hurt me, I went to cry afterwards in the toilet. 

This girl also often comes to my desk and asks me in a weird tone "what are you doing now", sure she is responsible for me but it still weirds me out especially her asking this and then looking at my screen when I write private mails to teachers.

All those things happening just gives me a bad feeling... I don't know how to interpret all of this, am I just overreacting? Is this normal?