**Trigger warning: mention of su*cide** should I tell my sister that my dad is su*cidal

So my Dad has been suffering depression and anxiety pretty much all his life but it been really bad recently, (pretty sure this is a genetic thing, and my family would probably all be diagnosed with some disorder if we went to a professional) a few years ago he was made redundant and he recently started a new job but has been struggling with pretty much every step. He has told me in the passed he was feeling like ending his life and today told my mum that he was really tempted to end his life. My mum's idea of helping is to make him Horlicks and give him a hug, all well and good but that doesn't help the fact he is clearly in need of professional help but won't even think of going to to doctors. My sister is dealing with a lot in her personal life involving her kids and her own health, so I feel like she already has too much on her plate. I know I can't handle having this information and if something were to happen I don't know what I'd do if I knew it was a possibility and hadn't warned anyone. I'm just a little torn on what to do, my dad won't go to a doctor and I don't know how to help him, but my sister is dealing with her own problems and has a lot on her plate already.