Eating fruit and drinking water can cause diarrhea in som susceptible people.
You can replace toothpaste and mouthwash with salty water (make it as salty as ocean).
Borax can be used for washing body and hair. Do not expect foam.
Part of your pain can be caused by eating fruit.
Some people do get more pain after eating fruit, especially if fruit is the only food they eat and if they have consumed a lot of Antibiotics or artificial hormones in their life.