I have a super-depressed friend messaging me right now, but I have also had to learn not to be "reflex rescuer" and allow others to steal my joy and spread their misery. I am allowed to have quiet time in the evening to process some photos. There are helplines if you are suicidal; I can't take it all on my own shoulders.
All we can do is listen, and ask them to pray for healing. Only God can do that, but they must be open to it and I think being at your ropes end it can shake even the most stone-hearted into looking to God.. You are a good Man Martin, the burden you feel is because YOU CARE.... God chose us all for a reason... Do what you can and then let go and let God... This is even harder when it is a fam member, trust me, they will see the light and lift their own burdens. You are doing the best you can. God loves you for it too... 💗