I don't think this is about suicide - he doesn't sound like he wants to die, or give any reason to really suggest suicide.
What seems more likely to me is that it's from the point of view of someone with a terminal illness or injury or something that means they're going to die.
"so if you believe, say a prayer for me"
I think that means pray that I'll live through it, but then he knows he won't survive because he goes on to say he won't be here tomorrow.
I don't think this is about suicide - he doesn't sound like he wants to die, or give any reason to really suggest suicide.
What seems more likely to me is that it's from the point of view of someone with a terminal illness or injury or something that means they're going to die.
"so if you believe, say a prayer for me" I think that means pray that I'll live through it, but then he knows he won't survive because he goes on to say he won't be here tomorrow.