Feeding on both sides?

I’ve been told that i should be offering baby both sides each time i nurse. But, he’s never done with either side. He will either nurse until he falls asleep, no matter what i do to keep him awake, or he will nurse until i have to take him off due to pain and irritation. If i take him off after 15 minutes and switch him, he will eat another 30+ or until he falls asleep. He’s 7 weeks old. If i pump and bottle feed, he still never seems satisfied no matter how much he’s eating. What am i doing wrong?