You're doing great! I found Day 5/6 to be hard for me, but now that I'm past that, it is getting easier. Day 10 was hard too, but once again, it was only 1 or 2 days before I was back to feeling GREAT!
By the way, is this your first MC? I'm on my third Master-Cleanse (not counting the times I tried and stopped due to bad timing...) My first was 16 days, and went very well. My second was shorter, but I'm now on Day 12, and going for 40. I belong to an online support group and there are several of us going for 21-40 days, so I get my support both here and there! It's such an important part for all of us to know we're in this together (and the committment help get us through those times we want to bail!)
Feel free to email me if you need someone to correspond with during your MC.