Talk to Neville.

"What happened, Neville?" you ask, looking at your fellow Gryffindor with a worried expression on your face.

"Malfoy", Neville explains.

He doesn't need to say more any more. None of the Slytherins had been nice to the Gryffindors after you were chosen as a second Hogwarts Champion. Even compared to their usual standards, the Slytherins were downright nasty. Gryffindors of all ages found themselves in the Hospital Wing after being cursed or hexed.

"I wish there was something I could do to help you", you say. "I guess I could get **** on Malfoy for you."

"Actually", Neville says, looking a bit embarrassed, "there's something you could do. You could teach me how to defend myself in case any of the Slytherins try anything again."

You think about this for a moment. Teaching Neville Defence Against the Dark Arts would probably be the most useful thing, but it wouldn't sate the need for **** that you feel at the moment.