"You always give your best as a player but sometimes you can have problems mentally," he said.
"It was difficult to concentrate on football after my father died but I feel it is all behind me now. Sometimes things just need time for you to recover.
"People don't know what is happening with players behind the scenes. Everybody knows I have had a hard time privately, and I am just coming out of it.
"I've played better in the past few games, I have scored a few important goals and I have provided a few assists.
"It was the first time anything like this had happened to me and it has made me only stronger. Now I feel much better than a few months ago, I want to carry on and show I am a good player.
"It would be really special to repay him [Benitez] by winning the Champions League.
"He is a really great manager. In the period when it was hard for me, when I had some problems, he was there for me.
"That he cared what happened to me outside the pitch means a lot. He is the best manager I've had.
"Playing football has been like a medicine for me. When you play great games, such as against Inter Milan in the Champions League, you can devote all your energy to what happens on the pitch.
"Hopefully, I can keep going like this and we can do well in the league and Champions League. We lost the final last year, we definitely want to be there again this time."
