I have a client who lost her 19yo son to suicide.
He struggled with depression for years. Probably around puberty and the time of his parents' divorce. She got him help and things were better while he was at home on meds seeing doctors. Then, he went to college, stopped taking his meds and got involved with on-line chats with people and suicide groups. terrible.
Before he hung himself in his dorm room, he went to visit a friend of his mom's who'd lost her teen son to a car accident. He did things around the house for her to help her out (things the son probably would have done had he been alive) and then he asked her how she was doing without her son alive. She told him she was coping, getting by but every day she missed him and was very sad. She downplayed her grief to him to keep things "up". However, as soon as she learned he killed himself, she'd wished she had never done that.

He was feeling her out to see if she was OK without her son so that he might know if his mom would be OK without him also.
His mom has gone one. She has another son who loves dearly and deserves her to live. She battled cancer and I have no doubt it was brought on by that great stress in her life (JMHO). She's still sad and grieves for him daily--never letting his memory fade. But, she has somehow went on--even alone, as son #2 has grown up and moved and she never remarried.
I don't know what your situation is but I will say a prayer for you, Seaspray, just in case your family is having a crisis. Suicide, attempted, committed or just contemplated is a horrible thing, a hard thing to bear as a parent. We second guess every parenting decision we make anyway, let alone to have over beloved child depressed, sad and feeling like they may not want to or aren't capable of going on.
And if you have a friend/relative who is dealing with this and not yourself, then all I can say is to be there to listen and support. It was all I could and can do for my friend. And I think it may just be enough.