i think i need to drop my high school friends

I have a group of friends from high school, hell some of us have been friends since elementary school. We're in our 30s now so it always felt special that we've been able to be connected for so long.

Around a year and a half ago, I was getting weird feelings from a friend, T. We were at our friend's bday dinner and she was avoiding me. She seemed like she didn't want to talk to me, which is weird since I thought in the group. we were the closest. I handed T a napkin and she glared at it like I had given her a smallpox blanket. Her sister was also there and she was acting upset with me. It was all strange and I just chalked it up to a bad day.

A few months later, I see that everyone went on a weekend trip, including their partners, and me and my partner were left out. This is weird because we function as a group, leaving someone out is unheard of.

When I brought it up in the group chat, T reached out to me via text and said that she felt our relationship had run its course. I said I would call her about this and figure it out, since to me it seemed like something that connection and time could figure out.

Anyways, she was uninterested in any conversation about it. Said if she was over it, I would get over it too. Okay.

For months now, I see them making plans without me and posting it. I don't know when this became a group issue. The thing is, when I talked to the others about it, they say "Oh T planned that and I didn't want to interfere with her plans." Her plans to exclude me? What? It makes no sense to me.

Anyways, I've been struggling with this for a long time and want to be rid of it. I don't know why the other girls are letting me be excluded, but it's happened so many times now I get the feeling they just do not care.

Our friend, N, has a wedding in about a month. I'm part of the bridal party. I felt like I wanted to go, but now I have so much resentment growing for them, I don't want to celebrate the marriage at all. I don't know what the right thing to do is.

Do I dip from the wedding entirely?

Do I go to the tea ceremony and wedding and that's it, I'm done with them no conversation?

I hate the idea of spending time with these girls after they've shut me out over nothing? (At least, they've told me nothing after I've tried talking to them about it)

For context, they are extremely adverse to confrontation and I'd imagine them ignoring me is their way of dealing with my presence. I for one, like to actually address issues before they become too big.

I got in an argument 3 years ago with T, but I apologized even though she said something awful to me about another friend, and she realised in the moment that ot was incredibly bitchy. I did not get an apology.

Do I give them one last message before leaving completely? I hate that they will probably be like, "Yeah I don't know what happened,we just stopped talking!" when they have been obviously excluding me from friend events. This fallout is on them, not me.

Anyways, I have other dear friends I've made over the years so I'm not alone. Just fucking confused and hurt.

Do I pull out of the wedding celebrations? Or show up one last time for this friend and just make my peace and leave? Or go full scortched earth and tell them how I feel.