Hello. I'm new here so I apologize if this isn't the right thread for this. I'm also sorry if this post gets a little lengthy, but I'll try my best to keep things to the point.
Around three years ago I met a really nice girl through a mutual friend of ours. We instantly hit it off, exchanged numbers, and quickly became good friends. We live over 5 hours away from each other and have busy personal lives, so we didn't get a chance to hang out in person very often, however, we would text and talk over the phone a few times a week.
As we got to know each other better, she started to reveal to me that she struggles with a lot of mental health issues. I had no problem with that since I was diagnosed with bipolar myself and could understand some of her hardships.
Every now and then she would call me (usually in the middle of the night) crying and venting to me. I didn't really mind since it only happened a few times, and I also wanted to try my best to help and support her in any way that I could. But, suddenly, these midnight calls would happen on an almost weekly basis. She would cry on the phone with me for hours and I would stay up late into the night trying to give any advice that I could. This continued to go on for several months and we soon rarely talked about anything besides her and her issues. Its like I was no longer her friend, but her own personal therapist. The relationship became entirely one sided and she was never interested in anything I had to say.
I genuinely didn't mind comforting and supporting her, but anytime I suggested that she see a therapist and get help with her anxiety and depression, she would completely blow me off and change the subject. She would refuse to see any professional and would tell me that she didn't trust them. She would tell me that she's fine and didn't need help, but then would call me multiple times a week when she was having a panic attack or a depressive episode.
I started noticing some red flags and I decided that I should distance myself and create some healthy boundaries. I told her that I would no longer answer her calls or texts at night because I had work in the morning and needed to be well-rested (which wasn't a lie) and that if she had an episode during those hours she would need to contact another friend, family member, or professional. However, this never stopped her from blowing up my phone with dozens of text messages and voice mails.
I truly felt sorry for her and wanted to help her with her situation but any advice I offered her went in one ear and out the other. It started getting to a point where I was constant helping her with her own problems that my own mental health began to suffer - which I took very seriously as I have been going to a therapist and working hard for many years in order to live a happy and healthy life.
I decided to back out of our friendship as much as possible. I didn't want to be harsh and just ghost her, but I instead slowly responded to her calls and texts less and less. It got to a point where we would only talk about once a month or less and she wasn't sending any late night calls or messages anymore either.
Every single time that I would start trying to distance myself from her or back out of the friendship, she would text me and say that she was going to commit suicide but then would later admit that she didn't actually try anything.
This happened again for the fourth time this week, and I honestly don't know what to do anymore. I feel like an absolutely horrible person for saying it, but she has taken so much out of my own health and even personal time with my family that, as much as I want to be a good person and help her, I can't stand being in this "friendship" anymore. However, I'm afraid that if I'm upfront about breaking things off and leaving for good, she'll actually attempt to take her own life.
I'm so lost as to what I should do and I'd really appreciate any advice you guys may have.
Thank you,
TLDR - My friend refuses to get treatment but threatens suicide whenever I try to back away from the friendship.