Completely sabotaging and preventing any kind of social media would also be a good choice. However, before technology made us "always" connected, and gave the ability to know anything at anytime I feel like people lived more. They had to go out and do things. Perhaps you could say they were even a bit nicer. Of course, that's not necessarily the internet's fault, it's ours. I think we simply forgot the part about moderation.
In the end though, a time-machine would be fundamentally useless. There's always going to be something that causes problems. The butterfly effect alone would make the world unrecognizable when you returned -- provided you still existed.