First of all, maybe you HAVE said it all in the first verse. Some stories are shorter than others, some jokes get to the punchline faster. If you haven't covered all of these in your first verse, that may help you to expand upon your lyric in the second.
Verses work well if they all relate somehow to each other, and all to the chorus.
The chorus can sometimes give you a clue as to how to expand upon your first verse and tie that in with your second. Think of using a timeline, past, present and future. The point is that sometimes it's just a psychological rut you've gotten yourself into, and moving the first verse to another position might get you out of it. Ultimately, maybe you have nothing more to say. Maybe there isn't enough of an idea for a song lyric.