I am having difficulty with the C Chord. I can get the stretch and fingers are arched to arrive perpendicular to the board and pointing towards my face as per the video. To push down the 1st string strongly enough to give it a good sound, my index finger touches either the G or E string (mainly the E string). I am pushing on the string on the tip of my finger just under the nail. I have filed my nail. I have put my thumb on different parts of the neck and put my palm directly against the neck or hanging below the nect. I can get the note to sound ok but either I don't push hard on the index finger which makes that string sound bad or I do push in which case I hit against the E string. Thanks for any advice.