I would also be surprised if I had a normal bowel movement after rice, chips & 1/4 naan!
Going back to the problem, most GPs have a few appointments blocked off for emergencies. I don't especially like telling my medical issues to the receptionist but I would if I had to to get an appointment. I'm lucky - I live a couple of minutes walk from my GP and have simply walked around at 8am when I've needed one of those.
But you have symptoms that would seriously worry me if I had them - black tarry stools, and pain and cramping in your legs due to them swelling up.
Are you on any medication other than the insulin?