I understand your fears. I am wondering if you don't just have a intestinal bug right now causing the change in your stools. I have the IBS and I use Fibercon tabs which work well.
I would be concerned about
your weight and the diabetes. Do you have a glucometer so you know what your blood sugar is?
It is difficult to go to the physicians office but if you have been gaining weight and not sticking to your eating plan I woul like to see you choose the physician's visit to get back on track. So please think about
Have you taken anything for the diarrhea?
You said you are fatigued, your electrolytes may be a bit off too but again the best is to get the opinion of your professional.
I hope you are soon back on track. Keep posting.