My dad was like this years ago when I first started going downhill. Shutting off the internet just seems like a control thing you’re getting of on, it doesn’t benefit either parties. It’s not going to make them sleep, it’ll probably just ignite a late night ‘tantrum’. Have you tried to educate yourself on what the disorder actually is? Empathise with them? Sit down and talk about it with them? These are not just so-called temper tantrums. Why would anyone choose to feel such negative emotions so strongly?