Hello wooowoo.
I would recommend that you go to your local ER, because it sounds as though you are dehydrated from the diarrhea! At your age, trying to rehydrate yourself could be dangerous simply because you are already feeling dizzy and weak. Those are normal signs of dehydration, and typically for younger folks, I would suggest drinking sports drinks such as Gatorade to help rehydrate you. BUT given your age, and lack of knowing your cardiac history, I would be very reticent in suggesting you drink those as they can lead to cardiac issues starting or getting worse if done in excess. At this point, we don't know what your potassium and sodium levels are, but the chances that they are off kilter are relatively good. Potassium is depleted from our bodies when we have diarrhea, and since it and sodium are the major cardiac electrolytes I will not suggest you use the replacement drinks. Please go to your LOCAL ER soon! They will connect an Intravenous line to you and provide you the much needed nutrients as well as check your chemistry levels to know which are needed most by you now! They will also run other tests (mostly blood, but perhaps stool and urine as well) to determine if what you have is a virally based pathogen or bacterial! Good luck to you dear!
You could just be suffering from what is just a normal stomach bug or virus. You need to drink plenty of fluids to stay hydrated. Most of the symptoms you wrote about can be caused by being dehydrated. Sports drinks are a good way to stay hydrated.
Possibly poor digestion and inflammation. Try going grain free and low carb for a couple of weeks, and check if symptoms get better. This has helped a lot of people as what you have is pretty common. Check out the book called Wheat Belly. What you have sounds very familiar to symptoms described in the book.