Cleansing reactions are normal while making those drastic changes. Especially if you've stopped any previous habits such as coffee/tea etc. I've read that vitamin C throughout the process helps detox go much easier. I believe it was around 500 mg in the AM and PM. Your body is just dumping old stuff...and it doesn't feel good in the process.
I remember many years ago doing a major fruit cleanse. First off, the cramping was agony...plus it really alters your life for a bit. You need to stay close to home if you catch my drift. I didn't know about the Vit.C back then.
Vitamin C is also a natural laxative if you need help there...just take it to bowel tolerance. For that, I've taken 1000 mg or more several times a day.
Maybe you need to slow your cleanse down a bit and let yourself go more slowly?
Good luck...it will be worth it soon. You might try looking into other products who are more friendly too
Pam