I agree you body is living and knows how to heal itself. It is awful to have to go through these pains.
I am currently fasting, and my right knee is killing me. I hate the pain. I am massaging, heating, and trying to help it heal. These painful moments are tough. I cry sometimes because I feel awful.
What helps me is my ability to see changes in my body. After a fast my digestive track works so much better. My skin is looking much younger and healthier. I feel great.
I have to go through the pain to get the results I need. My body is still toxic and one of these days I will get to day 30 and completely clean myself out of this junk.
For now I go along with what I can do and refeed when I feel good. Sometimes that is 7 days, sometimes that is 4 days, and sometimes it is 14 days.
It is hard to see what is happening on your insides, but know your body is cleaning out the junk as quickly as it can because it hates the junk. It is thanking you for letting it clean out the junk. Your reward will be seen on the outside, and will be felt throughout your body.