It’s common for people to get into roles in a friendship group. One person somehow emerges as the leader. Another person is the one who is funny. Still another is the helpless but cute one. You get the idea. There are lots of possibilities. Then there is the “helper” role, the person that everyone counts on to be there when other people are troubled and who always seems to have a shoulder for people to cry on. It sounds like maybe you have taken on that job in your group. It makes sense to me that someone as sensitive and giving as you are would be in that spot.
There is no problem with people generally doing what they do best. Problems happen when someone wants a break. Sometimes a leader gets tired of leading; the class clown wants to be taken seriously — or the helper can use some help. People around them don’t know what to do. They expect us to stay in our role because that is predictable and safe. It’s uncomfortable for the others to think that the helper might need a turn being helped. Then have to accept that maybe she isn’t always going to be there for them when they need it.
I hope you have a best friend you can confide in and ask for help. Then do what you can to expand your role. Yes, help people when you can. But don’t be shy about asking for help when you need it. People will eventually get used to the idea that sometimes you want to be on the receiving end of help and comfort.
I wish you well.