Hi Mimi,
It's also possible that a medication that has been effective in the past stops working due to changes in your weight, metabolism, exercise levels or eating habits. Would you tell me a little more about how you are eating. Since you don't like meat, what are you substituting? I am not a huge meat fan either, although I do eat some; I try to make a number of meals vegetarian choices every week. I spent a number of years eating a completely vegetarian diet and since that time there are now a lot of soy, plant, and vegetable protein based foods that I didn't have years ago. For example, there is a brand called Quorn that is made from mushrooms and has been turned into a ground meat substitute (great for tacos, chilli, meat sauces), burgers, "chicken" patties and nuggets. I find that my hunger is more stable if I get enough protein in my diet and there are ways to do that without consuming meat. It is also important to limit carb portions (perhaps 45 grams per meal) and make them complex, such as brown rice and whole grain or low carb/high protein pastas in appropriate portions. Have you met with a dietitian to see what you might do with food choices to improve your blood glucose?
Milk thistle is known to help the liver heal when it is injured; I will have to do some reading but I have never seen it indicated for diabetes. There are supplements and herbals that have shown some evidence in helping to improve blood glucose, but I would recommend seeking the advice of a licensed practitioner such as a naturopath before taking these kinds of medications as they can have side effects and interactions with your metformin. Please don't get me wrong; I am a strong advocate of alternative medications as long as they are prescibed safely, have evidence of effectiveness (sometimes this means studies in Europe, where they are more commonly used), and are monitored to make sure they are notr causing harm.
Kind regards, Laurie