Help me

My little one will be 6 weeks tomorrow. It takes minimum 90 minutes to nurse her on both breast. My neighbor, doctor everyone is saying it's a bad thing to do. U should give only 15 minutes on each breast. She is not happy or look satisfied if I nurse her for 15 minutes. I'm totally confused. I'm FTM, I have no idea whether I'm doing the right thing or not. I don't want my baby to be in hungry. Help me