I did not use social media while in college. I did not find my life to be much different from then on, if at all. I actually did better, academically speaking, because I stopped spending so much time looking at the "perfect lives" of others, and countless stupid posts of photos with food and girls posing in the same manner in every photo. I think I actually slowed down the loss of brain cells by a lot.
I had a lot of friends, and the ones that I wanted to keep in touch with were added to my phone, so we texted/called instead of "facebooked". When not studying or at the gym, I was exploring hobbies, doing research, hanging out with friends (a lot), so I didn't find it to have any negative effects on my life. In fact, I was probably happier. It's quite sad that people (read: many, but certainly not all, people) spend so much time polishing up their facebooks and looking at others' profiles when they could be doing things that are much more fun/substantial/meaningful. You won't die if you don't see what everybody is doing all day.