AITA for being upset that my friends are dating

I’ve never posted before so i’m not sure how to start this but i guess i’ll start with some background me (19) and my friend who i’ll call Ava (19) have been friends since we were like 8, around 3 years ago we became friends with a guy i’ll call James (17), after being friends with James for about a year i started to develop feelings for him, i told him after a few months and things didn’t go too well but we were able to stay friends and still stayed very close, a couple months after that he confessed that he had feelings for Ava, i was very taken aback and my first instinct was to ask Ava if she would ever date him because i’m a very paranoid person and i knew if she would ever consider that i wouldn’t be able to stay friends with them, she promised me she wouldn’t and reassured me everything would be fine.

not quite a year after that all of our dynamics started changing a lot, we all got a lot closer and more flirty with each-other and while my feelings for James never changed i started developing feelings for Ava too, eventually James told me he was planning on telling Ava how he felt and i realized it wouldn’t be smart for me to hide how i felt anymore so i told Ava the same night James was planning on telling her and she told me she felt the same way, and that she liked both me and James but after that no one brought anything up for a couple days. Then James told me we needed to talk and he told me that him and Ava were gonna start seeing each other, i made it very clear i wouldn’t be able to handle that and that if that’s really what they wanted and were planning to do it would be better if we went out separate ways but they were very against that and were sure we could figure it out and make it work and they made me feel very guilty about even considering putting my feelings first despite the fact that i know myself and i know my feelings for them wouldn’t change and it would eventually lead to me resenting them because im a very jealous person, but i stayed because i loved them.

Its been almost six months, and they’re officially dating now and i’m still not okay with it, my feelings for them haven’t changed and i can’t stand it when they leave me out, James doesn’t even talk to me much anymore so it kinda seems like he just used me to get to Ava but Ava still acts like she has feelings for me when we’re alone. I hit my final straw today when i saw their initials in each other bios but i feel like such an asshole for hating them because they’re together, but at the same time why did they expect me to be okay with this and why was i expected to sacrifice my feelings so they didn’t lose a friend when i made it so clear that i knew this wouldn’t work, i don’t wanna lose them because they’re my closest and only friends but am i crazy for thinking they’re kinda treating me like shit? or am i the asshole?