The noise in the room next to me was preventing me from thinking.

I'm thinking about going to Switzerland this summer.

Little boy was denying that he's always abused and punished (я не знаю, где здесь употребить герундий т.т).

I insist on talking to him.

I was looking forward to seeing my brother.

I don't feel like playing lotto today.

She succeeded in translating this difficult text. 

Thank you for sending me such beautiful flowers.

He was accused of selling state-owned secrets.

He was denying that he sold them (тоже не знаю, но я б так сказала).

He was afraid of putting in prison.

He was protesting about treating him like a criminal.