Overall I don't particularly like it. I don't like the heartbreak songs so call me bias. But the opening verse is good except for the last line, I feel like I've heard that one a billion times.
youd be better off dead in my book - a no go. You could still say the same thing, but do it more creatively. That line as it is, is pretty cliche.
I don't know the first thing about songwriting so I'm only saying what I feel right now. So keep on delving, you can only explore further.