I don't know why life at times hurls the most awful shit possible at us.
Words of support and comfort only go so far but are helpful.
All I can say is I've experienced all of what you mentioned and it's heart breaking and crushes the spirit.
In a short period of time I lost the lady of my life and had her use our child against me. Then both my adopted sisters got mixed up with drugs and shortly after my step dad was diagnosed with early onset Alzheimers. 2 years later I was wrestling him to the ground with an EMS team to sedate him and carry him out of his own home. 6 months later we buried him.
Plenty more awful shit I won't elaborate on...
What has given me hope is that, when the painful memories fade, I am a wiser and more content person.
Wishing the same for you brother.
Scott