having but not having

my "friends" hung out with each other yesterday without me,, i didnt know until i saw one of them post it on insta. i mean like its fine to not want me to hang out with them but it just kinda hurts. a major one of my fears is missing out and i fear that im missing out rn on having good friendships. like they arent bad people i really like them- but i just feel like they dont like me, at least not enough to wanna ask me to hangout sometimes,, and id be so much more fine with it if i wasnt the only one that wasnt there. i hate being excluded,, im not sure whats wrong with me and not being able to keep friends. making friends is already so hard for me bc of my anxiety and fear of rejection. i feel like i most of the time self invite myself. like sometimes they have plans and im like the last one to know or be asked. but idk maybe im overthinking but i really dont think i have friends.