About the Charity phase

[Axoloth]

So, the other day I was in a strange position: I was the lowest level, and had five monster cards and one item card at the end of my turn. I didn't want to play the item card because I wanted to keep it a secret, and the rules said I had to play cards to get down to five, OR give/discard cards.
Now, does that mean I first and foremost have to play all the cards I can play OR give away cards IF I don't have any cards to play? Or does it mean I can just choose to discard a monster card and keep my item card a secret?

I'm asking because the "can't discard cards just because you want to" rule made me uncertain.