Hi there - Is there any relation of your taking Metformin and the onset of the chest and arm pains?
I was at an event on Monday where a lady with diabetes was talking to me about how she was getting along and so on. Curiously enough she mentioned that Metformin had given her chest and neck pains, which made her feel very unwell. There wasn't any immediate connection between the two, but she (unilaterally) decided to take a break from Metformin (as she had been having a phase of tummy reactions and she couldn't cope with both). Within a week, her pain had gone (and her tummy was better), so she decided to try harder on her diet.
Now, I had never heard of this acute chest pain before, and we see a few newly diagnosed T2s through the forum, so it may not be a common thing.
I'm absolutely not suggesting you have the same thing as that lady, but it could be worth asking the medics next you see them.
I do hope you get some clarification soon.