Hi @abcdefg
It can be really hard to be that pillar of support for people especially when you don't have one for yourself. I'm sorry to hear that you have had so much on your plate. As for your friend's situation, I don't believe that you should see yourself as selfish at all. You have been so selfless in being there for her through her troubles despite you having a lot to deal with in your own life. Putting some distance between you and her is not selfish. It's just you taking care of yourself and prioritizing yourself more. You are looking out for your own mental health and well-being which is healthy.
What might be beneficial is to communicate. Have you been able to talk to her about how you feel about the situation in that - you want to stay close friends with her, but you also need someone to be there for you and support you in the same way that you do for them.
Also, do you guys have any school psychologist that you are able to get in touch with and talk about some of these experiences you have been having?
Hope you are well 💙
