i can kind of rhapsody. I'll my friends always lean on me then when i need somebody they're never around. Its hard sometimes but you just need to learn to take care of YOURSELF. YOU come first. If nobody else can be there for you, you must be able to understand that you can't do everything.
You can't always be there for everybody, and it doesn't make you a bad person or anything. It just makes you human. Nobody can do everything. They would go crazy. They will understand if you tell them you have something else going on that day.
Just remember that YOU come first. Everybody else in the world only thinks of themselves, and you should try it once in a while