The singer and actor came in second to Kelly Clarkson on "Idol" in 2002, but his career has stalled in recent years.
Guarini, 34, revealed surprising details about his living situation in a blog Wednesday, noting he spends "days skipping meals in order to make sure I have enough. To make sure my children and my wife have enough."
"I'm unafraid to say that I am terrified," wrote Guarini, who is married to Reina Capodici, the mother of his two young sons. "I am struggling to make each day meet the next without breaking down and curling up."
He went on to say life "ain't perfect," but it's "filled with love."
"I have a wife whom I love and who loves me [me!] and who lifts me up. Children who give me cherubic-lipped kisses before I leave for work and who are the most delicious morsels of joy and peace and prosperity," he said.
People.com said Guarini will play the supporting role of Paris in the upcoming Broadway production of "William Shakespeare's Romeo and Juliet," starting next month.