Hi David,
you don't tell us how old you are, but with getting fairly strong symptoms, yyou may be a type 1 (usually young, but not always)diabetic. Type 2s may have only very slight symptoms and often no weight loss. If you are T1, Metformin won't help you and they'll find out fairly quickly and put you on to insulin.
Did they give you a Blood glucose meter or tell you it isn't necessary for you to test yourself?
Anyway, one thing that can help T1 AND T2 is to cut down on the carbohydrates you eat. Carbohydrates are the nutrients that turn to Glucose in blood and it's going to help if you have less.
that means cut out sugar and sugary foods ( If it's sweet and doesn't have artificial sweetenr, don't have it) cut right back on floury foods. Anything that started as a grain, or starchy root vegetables like potaotoes or parsnips.
Eat as much as you want of meat, fish, poultry, cheese, eggs, tofu, TVP and green leafy vegetables.
Be careful of fruits. (If it's sweet, it contains sugar.!) You can have cream and butterBut be careful what you put them on
Our favourite snack is Macadamia nuts. Brazils and almonds are almost as good.
You are on a steep learning curve. the quicker you find out what suits you, the quicker you will be able to get back to non-diabetic blood sugar levels. It's the target to aim for and IT CAN BE DONE.