Is egocentrism toxic? Should I also rather avoid such relationships. I don't want to lose everyone bc I'm the one who's difficult and can't take anything.

The issue is: we need friends, people who we trust and with whom we can share the ups and downs of life. It's people with whom we feel comfortable (when you leave a friend, you should feel more secure in yourself and in the friendship). Friends take care of us: they are interested in our lives, and they learn to notice when something is wrong. Even if we don't see them often, we are happy when we meet and we know we can ring them for support if needed. Sometimes it's family, sometimes we need to build our own.

At this point your sisters don't do these things, so you can not consider them friends or allies. They are acquaintances. It's fine but you need a real network of support, one who will care about your opinion. You'll be more relaxed with your sisters when you have that because you won't have needs toward the relationship. I wouldn't break contact, but don't invest too much in it if you don't get this security and care in return. Also note that teenagers and young adults can outgrow this self-centered phase, so time might solve the issue.