Your first instinct, to limit your time with your friend, is a good one. You were attempting to protect your own mental health. You did the right thing.
In addition, you are not a therapist. It is not your job to treat her depression. Nor is it possible for you to do so. That is the job of mental health professionals.
You should encourage her to seek treatment. If she is unwilling, then you should continue to limit the time you spend with her. People have to be willing to help themselves. She may not like it and it may feel uncomfortable but your self-preservation, in this case, is paramount.
If she is unwilling to seek treatment, another option is to contact her parents. Tell them about your concerns. She may not appreciate your contacting her parents but if you’re concerned about her, it’s the right thing to do. It might ensure that she gets help for her depression.
Your friend needs help beyond what you can give. It is reasonable to support her efforts to seek help but you cannot act as her therapist. There are professionals who can help her. If she’s willing to seek help support her but otherwise, keep your distance. It may be unpleasant to endure her disappointment but it will pass. Stay strong. Good luck.
Dr. Kristina Randle