Feeling left out, and miserable.

So me and my main group of "trio" havent talked for a good while, but I just assumed they're all busy with their life, so I kind of planned for us to hangout finally and catch up. Skip to the hangout, we're talking about what we've been up to and they suddenly bring up stuff they did together last week....and the week before that and im like ?????????........ Oh. It gets worse though they show me pictures and videos of their hangout and at this point im kind of dying inside already.

Not only that, awhile after that one of my friends bring up sort of like an 'inside joke' between them, I guess, I dont know how else to explain it. So just imagine me asking "what happened? what happened?" the whole time while they're laughing their ass off.

Im so embarrassed. That whole hangout felt like a humiliation ritual.

Idk, they're allowed to do stuff together without me obviously, but i feel so devastated right now because for weeks I cluelessly just thought they were busy. they didnt once try and initiate a hangout. f.m.l