Feeling kind of down about my shower

My shower is next weekend. We invited like 40ish people, 20 have rsvpd so far. Out of those 20, only 4 were from my list. My mom, 3 friends, and one of them said they were bringing their SIL. (That SIL and I don’t get along)

Both my grandma and sister booked trips after receiving my invite. Like my sister called to tell me that her and my grandma talked on the phone about it and decided to book trips that weekend.
On top of that, my grandma said she will not be attending my ceremony or reception. (I am having a private ceremony for just immediate family and a reception the week after)

I’ve expressed my feelings to my sister after she told me it’s not a big deal, but it feels like a big deal to me. My family is treating the biggest moment of my life like it’s just another day.

I’m just so upset over it. I’ve cried so much over it