Was told to keep this secret from everyone I know, including my cat

My best friend (32f) told me (31f) last night she’s eloping and wants me to be the witness for her and her bf. And I’m not allowed to tell a soul.

There’s a bit of a back story but I have a ton of thoughts running through my head about all this and since I can’t even tell my bf I need to put it somewhere so I don’t feel like I’m going crazy

I am very happy for her before you ask but it’s just a lot right now