Hi Ange1a65
Welcome to the forum. You'll find a lot of friendly support and extensive knowlege/experience here
Regarding your symptoms, I can only suggest you see your doctor asap as you may be reacting to the Metformin. See here,
https://www.drugs.com/sfx/metformin-side-effects.html, for a comprehensive list of possible side effects.
With regard to your not passing much urine, I wonder how much you are drinking in a day? You really need to drink approx 2 litres to keep well hydrated. With sweating you can be losing a lot of fluid through the skin which could account for some of the low output. However, I still think you must discuss this all with your GP. Maybe take a urine spec with you too as they will be able to check that.
I do hope you are feeling better very soon. Metformin is known to be badly tolerated by some people and there is a Slow Release Metformin. Of course it is more expensive, hence the surgery prefer the 'normal' version. Gastric upsets are very common and often, but not always, settle down in a week or two.
I wonder if you might have changed your diet since diagnosis? If you have suddenly cut out carbs, for instance, you could be experiencing 'carb-flu' but also you could consequently also be lacking the roughage in your diet if you've cut out bread/potatoes/pasta/rice etc.
I still say you should visit your GP in the first instance. If your rash gets any worse, or your breathing becomes affected, stop the Metformin but still get an urgent appt with your doctor.
Good luck and do post back
Julie