Anja, are you drinking after 2 pm when flushing? Dehydration was my biggest problem until I learned to drink, drink, drink ... just not 20 mins before or after each flush cocktail.
The dizzy feeling can be the toxins that you're reabsorbing/recirculating when they are first released from your liver. The fact that you feel better after you GOOOO is my clue here. Drinking plenty can help you start GOING sooner.