I lived without getting periods for three years. Is it due to PCOD?

Hi doctor,

I am a 25-year-old female with two kids. The first child is seven years old and the second child is four years old. I was getting an injection for three months after my second child was born. I got it for a year and stopped it because it made me feel sick. Then I started noticing that I am not getting periods. After waiting for periods for a year, I went to a gynecologist and she told me that periods will come and advised me to wait patiently. After that two years passed, I did not get my periods. After three years, I went to another gynecologist and she told me to do blood tests. The blood tests showed that I have insulin resistance and she prescribed me Metformin. I am taking it for two months now and I got my periods. I have heavy bleeding for three weeks with dizziness. My legs are paining and my back is also sore. I have constant headaches with fatigue. Please help me.