Re: foamy, persistant diarrhea
You need to give your stomach and bowels a rest. You may need lactobacilli and digestive enzymes, too. Look for Native Remedies or Natural Healing House.
Try this diet for one or two days:
breakfast/lunch/dinner: veggie soup (potatoes, carrots, celery, etc very well cooked and then mashed and pressed through sieve)
On the third day, if you are feeling better, add one cooked egg to the soup (lunch and dinner) and mix thouroughly.
On the fourth or fifth day, add some minced chicken breast or fish (lunch and dinner) and so on until you are able to eat your normal diet.
Avoid dairy and wholemeal products for a while. Eat very little fruit or maybe fruit juice, but always as a snack one hour before dinner. Fruits must be a separate meal.
It doesn't help you to think about worst-case scenarios.