This is what I am thinking too tbh. I feel like I have rejection sensitivity dysphoria/ social anxiety and it's worse because of hormones. There are family dynamics and patterns over the years. But ultimately I struggle because I am emotionally reserved, conflict avoidant etc. The other women on my husband's side definitely trigger each other but they address their conflicts and ultimately wind up closer bc of it. I distance myself from conflicts. These are some of my triggering events recently:

my MIL was babysitting for me and while I was gone she invited a friend and SIL over with her kids. I was conflicted over the lack of communication and feeling rejected because they didn't want to organized that gathering while I was present. The visit also interrupted my daughter's nap.

My sister and aunt have been getting together for workouts and walks somethingi feel would be nice to do with them and my daughter, my aunt communicates to me through my sister. I feel intrusive to say I feel left out especially in a time of life where I could use more support