I have a group of girlfriends, most of which i have known since high school (about 20 years).  Recently (within the past year) I have been joining their group on social outings, birthday dinners, drinks, get togethers with the kids, etc.  At the beginning of November we all did a 5k together and went out to dinner that night.  Since then, I have been invited to ONE gathering, which included all the children and involved bringing food and gifts.  The rest of the ladies have gotten together at least six other times, including a New Year's gathering.  I have not been invited, and have seen multiple posts on fb about all the fun.  

Recently one of the ladies posted about planning a trip and asking for recommendations.  I asked about the trip and she said I was welcome to come, giving me dates, hotels where they have reservations, etc.  I replied that I didn't know they were that far into the planning process and didn't want to intrude.  One of the ladies I am quite close to (exercising with her four days a week) and I told her I felt excluded.  She said they had planned the trip as a celebration of her upcoming divorce finalization (which she and I have discussed at length) and I SHOULD come and I shouldn't feel excluded.  I just dropped it at that time.  Two weeks later, same friends posting about an outing that I again wasn't invited to.  

At that point I unfriended them, thinking that they don't HAVE to invite me, and if I don't know about the outings then I won't feel excluded.  My closest friend texted me to ask why I unfriended them and I told her.  She said that they weren't intentionally excluding me and she didn't intend to hurt my feelings.  I told her I understood, and I didn't think she was doing anything wrong, I'm just protecting my feelings.  AITA for unfriending??

TL;DR: my group of girlfriends keeps excluding me so I unfriended them so I wouldn't have to see what I'm missing. AITA??