duo in trio

so I have this one trio, we were friends since 3rd grade when I went to this shool in 3rd grade. we had a good relationship until 4th grade, they weren't talking to eachother. I helped them get back tg. during 6th grade, they literally and suddenly found a new person to replace me? not that they told me: "oh we replaced u with a new girl", but they hang out with the her more oftenly than me. I rlly want them back. I have a squad but, I don't feel the same like how I did with the trio. I also have trouble venting w people cuz I don't wanna be a burden