need some advice!

so recently ive felt like my group of friends have been leaving me behind. i had a test last week or so and it was like...a small presentation i had to give to my teacher. it was honestly a 10 minute presentation. my friends finished theirs before i did, and wanted to out to a nearby shopping mall for lunch. i asked for them to wait for me, but no one seemed to care, and refusing to wait.

i understood that they were probably impatient and wanted to go to eat, so i just let it go even though it kinda felt like shit to be left behind. so i let it go, thinking to myself i'd catch up after i finish my presentation.

i walked alone to the shopping mall, and tried to contact them so maybe i could still have lunch with them. no one responded, and just read my text. 

ok, fine, whatever, they might be eating or busy. so, i ate with one of my classmates that i happened to pass by. It honestly sucked, but what can i really do?

i'm really bad at being mad at people, because i do forgive really easy even though it feels awful. a week later everything seemed to be normal. and i decided to forget about it. fast forward to yesterday: there was an activity that the school offered for people to sign up, and i didn't know about it because no one told me. i sat alone at our usual lunch table, wondering where everyone went. i found out they were in a meeting room having lunch together to talk about the group activity. i don't know if that was intentional or that they genuinely forgot about inviting me, but when i asked what the group was about they told me that the school's slots were full.

i didn't eat that day.

some of them are ignoring me (not in the way they don't talk to me at all, it's just that they don't initiate conversation and ignore me when i walk or something). i don't have classes with some of them, and when they get into pairs or groups i feel really left behind. i feel horrible eating with them, because i feel like i'm the most boring person in the world and i'm considering just eating alone at this point or just not eating at all. maybe i'm just being dramatic, who knows.

i don't know what to do, and i don't really want it to become a huge issue because most of them still talk to me normally, it's just that i have really bad history of when my friends would become friends with other people and leave me, and i don't want that to repeat. I genuinely don't feel like confronting them because what if i find out they don't like me anymore? or they're uncomfortable around me? i'd rather not know than find out. 

this is really vent-ish so i'm rlly sorry lol i genuinely don't know what to do. if anyone has any advice to give me or what i should do, i'd be really grateful. i'm not sure if anyone would see this at all, but it feels nice to let everything out. (also i hope i'm posting this at the right category?????)