I find it strange I’m the oldest of my sisters and my younger sisters don’t include me in things

They tag each other in statuses and don’t tag me. They buy each other things and don’t buy me anything. The go on trips and don’t invite me. People probably don’t even know we are sisters probably... it’s kind of embarrassing publicly because some people know and I’m sure they probably know what’s going on... we have different fathers they three of them have the same dad. Who mostly raised me but they only call when they want something or if obligated simply because I’d text and say call me. We were separated at youth on the weekends every weekend they got to go to their dads house and I got stuck with the older brothers. And I’m barely close to them because they are close... it hurts 😢 It breaks my heart. I don’t say anything because I’m sure no one will understand or care what I feel or think about it all