Please help, suggestions

My dad is depressed and I’m a little worried about him. I don’t know why I feel the fear I do of losing him to this depression but I am scared. The last two nights he has come home late and been drinking,, not hard liquor just beer, but if you knew my father, you’d know, before the depression he might of drank one beer every 7 to 8 months ( not exaggerating)  his depression has struck a cord in me and In worrying about him I kind of worry about myself. I don’t mean to sound selfish, because I am not but if suicide were on his mind and he went through with it (though I do not know if it is on his mind) where would I be? Could I, Would I survive it? There is a heaviness in my heart tonight, a worry and I wish it would go away, because yes, I have survived many things, but where oh, where would I be without my dad. He raised me, hes the only parent in my life, I need suggestions to help him, yes I’ve been depressed, I’ve been down a dark road but I never had anyone pull me out of it, I did it myself and now I need to help him. I need help.