I have been meditating regularly since July 2007 and in the last three months I find my mind is constantly flooded with thoughts. It is very hard to concentrate on the syllable or even to sit quietly without the syllable (though the latter is easier than the former). Is this normal? Am I failing at this. At the very beginning it was very easy and I even felt an energy field. Now I feel frustration and find I am stopping earlier and earlier. Help!