It’s gotten to the point where I need some internet advice from strangers lol

I’ve been seeing this girl since November 2022, so about 6 months ish. She is a sweetheart and one of the kindest souls I have met. We play fortnite together and (tmi: she’s the best I’ve ever had in the bedroom). She’s given me stuffed animals that match my vibe and she’s also gotten me really cute/funny gifts (one of which is a button that when you press is says Bazinga in sheldon’s voice from the big bang theory). I am a standup comedian, and she is supportive of it and is (usually) okay with me being out 3-6 nights a week perusing comedy. Also we live at our respective homes and are about a 15 minute drive from each-other.

Here comes the complicated parts:

We never made things official but she has recently been trying to pressure me into it because it’s what she wants. I have been transparent since the day she and I met that I am not looking for anything monogamous. We had a talk the other day about how if we were to make thing official, I want to be in an open relationship. I’m fairly spiritual and I live in a very “fuck around and find out” way (I’m a comedian, it yields fun experiences and gives me great stories), but she isn’t down for that. After I recently reminded her how I want that at this point in my life, she kept saying how she’ll never be enough for me and that she was having thoughts of relapsing (self harm).

For more context she is extremely depressive and was recently in an intensive outpatient program due to suicidal ideation. Also her mother is an extremely toxic person in her life, and while the father is lovely, he enables both the mother’s alcoholism and her BS.

I do have a lot of love for her, and she is a sweetheart not only to me, but to my 3 younger siblings and my mother (who all adore her, and are also understanding of my situation). However, I feel like the situation with her is getting unhealthy, and I can’t put myself through a relationship with someone who needs as much support as she does. I don’t blame her obviously, as she has diagnosed mental illnesses, but even with those put aside it feels like I’m trying to jam two puzzle pieces together that just kind of don’t fit. She and I click in so many ways but we simply want different things. It sucks because we really do have love for each other, but I’ve been in an extremely toxic relationship before and I’m starting to see some signs that the relationship may be taking that turn. She’s said that she wouldn’t be able to handle being ‘just friends’ because we’ve already ‘done so much’. I really don’t want to break her heart and I REALLY don’t want her to not be in my life, as I really do care about her and I want to be there for her as she has no other friends, but I feel like breaking up is the right choice to make.

Any advice would be more than welcomed please 🙏

TLDR: She is a sweetheart but I can’t give her the support she needs and we want different things.