I am so sorry to hear about your situation that sounds so stressful! Am I right in understanding that you've had some concerns for this mate's mental health for a while now, but recently you're noticing behaviours that indicate things might be getting worse? That sounds like a lot to have on your shoulders!
In the past when mates of mine have been in similar positions I have had to remind myself that as much as I want to help and support them, it is their journey, and as much as I can continue checking in with compassion and holding space for that person, what happens from there is ultimately up to them! I think it is fair to say that this is something a lot of people struggle with as it is so hard to watch people we love go through pain, it is much easier said than done! But hopefully this experience can also be an opportunity for growth for this person too! That being said, it really sounds like you care for this friend a lot and again, I am really sorry to hear you are in this position!
Are you chatting to any one else about your concerns or are there others who can support you too? ❤️