My moms self destructing herself, what would you do?

My dad passed away 4 years ago. My mom is all I have left, she’s my best friend, we talk on the phone maybe 10 times a day and constantly FaceTiming because I have a little baby and it’s her first and only grandkid. My mom has been drinking a lot and smoking a lot and using my dads death as a excuse when she was doing it when he was here. She went to the doctor today and they’re sending her for a lung cancer screening 😥 because she smokes and gets out of breath and a blood test and she’s 60 years old.. just turned it. My mom is all we have left and I thought her having a grandkid would change her behavior. I also found out she stopped taking her cholesterol medicine because she ‘drinks’ instead. What can I do? I’ve tried everything I’ve been sitting crying all day. I only am 23 and don’t want both of my parents gone. What would you do?