What are these marks? Am I being paranoid?

I have recently been diagnosed with Type 2 and have been taking 500mg of metformin with meals. Since starting on metformin I have developed severe bodily itching akin to the eczema I had as a child. My skin looks exactly like in your photos. Do you also have itching? I suspect I am allergic to metformin and shall have to ask my GP for an alternative or at least get some antihistamines or cream to alleviate this allergic reaction. Your skin reaction could be an allergic response to either high glucose or to any new drugs you are being treated with such as metformin in my case.

Are they itching, painful or anything else?

At the moment if it were me, I'd be supremely unconcerned about it, unless I felt rough. I'd wager your aunt was in the less common group for amputees, in that hers seem to have been upper body. My understanding is the more commonly affected areas are the lower extremities.

A potentially comforting comment comment would be that redness usually indicates a decent blood supply, or a bit of an irritation/allergy.

Could you be reacting to a hefty rise in carb intake, versus more recent times, due to your birthday celebrations? The body doesn't like a chaotic routine, so maybe it's objecting a bit?

Keep an eye on it and give yourself a bit of a consultation:
Do you have any extraordinary aches and pains?
And headache?
Temperature?
Disrupted sleep?

If there's nothing too out of the ordinary, keep a good eye on it for a day or so. You have photos, so provided you can replicate the lighting conditions, you would have a comparison on which to assess later or tomorrow.

@Debmcgee

Likewise ... if that was me, I could not be less interested ... but do keep a watch out. Looks very minor so some soothing cream might help a bit.

Me and my children have this at the moment!!! No other symptoms just randomly started. I was told by pharmacist that it was either viral or an allergy