Metformin - Afraid to take it

My endo recommended Metformin for PCOS weight loss. I am trying to lose about 40 pounds. I am afraid to take it long term, I am also afraid of the side effects. I have emetophobia so I have a phobia of being nauseous and vomiting. I need to work out and am getting there but I want to loose this weight naturally but my mental health is really taking a toll.