The same thing happened to me. I was diagnosed with type2 diabetes. My GP at the time said I could not have type1 as I was too old at 68yrs. I tried to discuss this with him. But he wasn’t listening. I was prescribed metformin. I bought a accu chek to measure levels as I was losing weight rapidly very thirsty feeling unwell. My glucose levels were around 18/20/26mmols fasting I phoned the surgery and spoke to the same GP who advised I continue with the metformin. Also to have a blood test done. A week later the blood test confirmed type1. I was in hospital for two days on a insulin drip. Just in time. I had ketoacidosis.