In just four lines, the speaker describes a moment of unexpected clarity. For a while they have been caught in self-loathing, and they seem to have assumed that this meant they wanted to die. Then, with some surprise, they realise that isn't quite true. What they actually want is for life to start, as if the life they have been living doesn't really count yet.
That small shift changes everything. The speaker isn't longing for an ending so much as longing for a beginning, for something better than the stuck, painful place they're in. The phrase "deep in my self-loathing heart" shows how heavy those feelings are, but the last line turns toward hope, even if it's a fragile one.
The mood is quiet, honest, and vulnerable. There's sadness in it, but also a gentle relief at understanding oneself a little better. The short, plain lines make it feel like a private thought said out loud.