Answer?

I was searching for songs of worship and I came upon this video "Speaking in tongues of Holy Spirit-Testimony."

In this video, there was this verse which was said to this guy by a pastor. Matthew 17:21. It's taken out from the NIV.
I wonder...is this God's answer for me? To pray and to fast? I've tried for so long when I couldn't get some things out of my mind for a long long time. Is it that I should pray and fast to get over it?
Lastly, I saw another video. Which proves people wrong.