I'm in a constant downward spiral (I'm sorry it's long)

Im new to this app and I'm scared to talk about my issues to anyone irl so I'm just gonna lay it all out here instead, I've been depressed since I was 14 and I haven't talked to anyone about it and now I'm 21 and I'm falling apart, I've planned to k*** myself several times in my life but something always held me back, it's gotten especially bad now, since I was 14 I had limited my self to cutting once a month because it's easier to hide scars if there's only a few but now it's every day, and my health issues (which I can't really talk about) are holding me back from contributing in any way to my family which I still live with, I can't contribute financially or by helping anyone with anything. my whole life I've been the helpful one, whenever anyone needed anything they'd ask me, and that's how I've justified living, i literaly have no purpose if not to help other people but now i cant even do that so I have no reason to hold on anymore, and I can't come out as depressed because my folks already have enough stress on their plate, my parents already have 2 depressed kids and dont need a third, and my little brother looks up to me for advice on depression which is ironic, and my older brother will never say it but I'm sure he'll think I'm over reacting if I come out with any of this, but I'm having more panic attacks and anxiety and I can't open up about any of this apart from random threads online because I can't afford therapy, I've tried s**cide hotlines and talked to counselors but everything is a momentary respite from the storm that's always around the corner. I know this all this is dramatic but it's how I feel