My mom is dying

I'm 41 and have recently discovered that my 19yr old daughter is addicted to drugs. And a few weeks after i discovered that, i received a call that my mother has alzheimer's. Sooo, I thought i was dealing with everything as best as i could...but yesterday i received a call from my mom that she also has lung cancer. And im in a mentally and abusive realationship to boot(20 +yrs) and dont know which situation to tackle first. What do i do? I have so much depression and anxiety that i feel paralyzed.