Q&A: Toddler fights bedtime

Q: My 2-year-old son doesn't calm down easily for bedtime, and my wife and I need some ideas. We've always coslept with him and my wife breastfeeds him, and we're keeping to a bedtime routine, but a few months ago, our son began to really fight bedtime, even when he is very tired. I really need some help as it's really hard to not lose my cool when I'm still up at midnight tring to get my child to sleep!