AIO for calling my girlfriend (22f) a cheater after she jokingly flirted with another guy and added a guy who has a crush on her?

me and her have basically been a situationship for maybe a year and a half, she’s very very avoidant, we finally became official some months ago, and everything was going good it was sunshine and rainbows and we were so happy.

she used to talk to this guy in university, just platonically, but it’s very obvious he has a crush on her.
now I wasn’t comfortable with that and she stopped seeing him anyways.
some time later she made her instagram account public and some days later the dude saw it and followed her, she didn’t follow back, so far so good, then fast forward a month he see’s her in university and tells her he’s following her so out of manners she follows baxk which I can understand in the moment, but I do tell her that she should unfollow him since he clearly has a crush on her and he doesn’t know she’s taken since she wants to keep us private, i’m not personally comfortable with her having friends that are obviously interested in her.
she respected that, a bit hesitant at first but then she unfollowed him.
now fast forward a week later, and it’s like she switched personalities, she wakes up and tells me she’s really annoyed at me because the guy unfollowed her after she unfollowed him, claims I made her “lose a friend”, and tells me she went ahead and sent him a follow request. this upset me a lot and i tried to be really calm while talking her and explaining to her that this is a boundary, but she kept me calling me jealous and insecure and said that she’s not responsible for my feelings.
that same day she was playing valorant with a group of friends, she didn’t invite me even though we always play but i figured it’s cause of the fight, then on discord some guy starts sending voice messages with a weird deep voice, and her and the group of friends start making jokes, at one point she said “keep talking we like it”
one of the guys said “your voice makes me hard” and she said “ikr”
i saw this and i felt like shit, i deleted her messages since I have permissions and I banned the guy, when she saw that she took away my permissions and added the guy personally to add him back to the server.
at this point i already had a really long day and i call her and we get into a big fight, i’ll admit i was extremely angry and kept calling her a cheater and asking what is wrong with her and why does she keep hurting me like this. she says the instagram guy thing was cause i annoyed her and she doesn’t wanna feel controlled, and the flirting with guy on discord she claims was just “making jokes” and i’m taking it too far.
this all upset me so much, i felt so invalidated, then she got mad at me saying my reaction and my yelling at her and calling her a cheater is fucked up and no one should talk to her that way and she’ll make a serious problem because i talked to her that way basically threatening me, and then she kept telling me to break up with her.
i felt manipulated, it’s like she pushed me to the point of breaking by doing all these things then blamed me for my reaction, but in my defense how could I have stayed calm watching all this unfold in-front of me.
am I in the wrong? did I really overreact? i feel like what she did was cheating and her knowing these things would bother me is messed up. can i consider this cheating? if not it would be breaking boundaries and intentionally hurting me it feels.

an extra note: she is an insanely jealous person, she once blocked me on everything because one of my girl-friends sent me tiktok’s that I wasn’t even replying to. and sent me an entire paragraph cursing me out. so idk why she switches personalities and now believes i don’t have a right to be jealous.
another note: i believe im not a controlling person, i don’t tell her to cut people out of her life, i try to establish boundaries, she herself has a lot of online guy friends whom she plays with occasionally and i’m fine with that, but if I were to have 1 female friend she would go insane.

tl;dr girlfriend unfollowed a guy who had a crush on her after i asked her to, then followed him back because she didn’t want to feel controlled and blamed my jealousy, and in that same night she “jokingly flirted” with a guy online, i got mad and called her a cheater and now she’s telling me to break up with her because of my reaction to what she did