Составить 5 предложений с новыми идиомами на английском языке

А какой точный перевод?

1. I only had a little bit to eat this morning and now I feel awfully hungry.2. Rick is aware of the fact that he is but a little frog in a big pond in this huge company.3. Solving math problems is a piece of cake for him.4. My neighbour is a real gaga, she can not remember my name!5. He abandoned himself to despair.