Liquid Fast

I would like to start an all liquid diet of water, fresh vegetable juice and protein shakes and continue cardio and building muscle everyday. I currently weigh between 250-260 lbs and my starting weight was anywhere between 350-400 lbs
(I was too ashamed of my body to weigh in or take pictures). I juice post cardio( beets, cucumber, celery, broccoli, yams, carrots) and eat salmon, chicken and rarely red meat post workout and I have been consuming low amounts of carbs since January. I have never used supplements or protein powder before. Any knowledge and tips are welcome, if this is a stupid idea please let me know because i really don't have a clue.