You look to be getting there with an eating plan, but if you are eating to your meter, why are you still eating porridge? A very small portion spiked you by 2.7mmol/l which is too much. You need to aim for under 2mmol/l, ideally about 1mmol/l at 2 hours.
Have you tested a sandwich on your bread? Most of us find we can perhaps manage one slice, but not two slices.
Potatoes - jackets and mash should be avoided, but you may wish to experiment with one or two small new or roasted ones, using your meter. Sweet potato is a bit better, but could still spike you. Your meter will tell you.
I hope you feel better soon. You sound so miserable.