Though words are hollow comforts, they are all I can offer. Please understand that though I do not claim to have lived your life I have some true understanding of the type of pain and struggles you are experiencing.
I have some questions in case you would like to expand on your post. Answer the ones with which you are comfortable. You can PM if you'd prefer or ignore me completely; I am not here to burden you further.
How long ago did you begin drinking and at what age?
What is your drug of choice? When did you start taking it?
When did you last see your mother? Why were you separated?
Do you live with or near your father?
I am sorry that your grandparents are dying, but am very glad your father is a part of your life. It is so important to those of us with suicide as a constant, nagging, reminder of the easy way out that we remember the importance of our relationships and the devastation that our deaths can bring (just as you are unfortunately experiencing with your grandparents). We are all in this together and sometimes need to shift our burdens slightly in order to be able to persevere.
We are never really quite aware of how we influence the people around us. I hope it is of some comfort to you that your post has given me the impetus to live through yet one more day knowing that I have another companion on this road.
Regards,
Praetorian