SNS中毒って英語でなんて言うの？

If you are always looking at SNS sites on your iPhone, and you can't put it down, you can say "I am addicted to my phone."

Some people just live their lives through social media - even informing the world about the most boring of activities in which nobody is interested.
Example: "Henry's permanently connected to social media."
Example: "Liane is continually posting messages on facebook!"

If you say that someone is an addict, you mean that they like a particular activity very much and spend as much time doing it as they can.

He is a Facebook addict.
She is a TV addict and watches as much as she can.

Both of these sentences should help you to find a way to express yourself as best as possible. Examples:" I am addicted to social media. I check my phone every second". "A social media addiction is a 21 century problem".

"Social media addiction," describes that someone is addicted to mobile phone apps such as Facebook, Instagram, Whatsapp, etc., and uses the noun, "addiction," which describes to have a dependency to a mentioned activity.

"A social media addict," describes someone who is addicted to something and almost has the same meaning at the first example.

"To be glued to one's phone," refers to someone who cannot look away from their phone because what happens on their phone takes all of their attention and focus.
Ex : "Jack is always glued to his phone, I can't get him to do anything else!

1. She suffers from FOMO.
   FOMO means the fear of missing out.This
   is actually a real problem because some people
   have become addicted to social media in such a
   way that it consumes them.This means that they
   spend hours every day trawling social media sites,
   sending and checking updates, posting comments
   and always wanting to be the first to impart a bit of
   fresh news via social media.

   2. She is an online junkie.
   3. She is a web junkie.
      An online junkie is someone who is addicted to the
      internet and social media sites.Like a drug addict, they
      need their fix every day.Trawling the internet or updating
      and checking statuses and comments is the first thing they
      do when they wake up and the last thing they do before
      falling asleep.

Someone who is addicted to social media can be described as a social media addict.

For example:-
My sister is a chronic social media accict, she can't stay away from facebook and instagram not even for one hour.

If you are trying to describe someone who is addicted to using their phones or using social media in specific, you can say something like "A social media addict." or "Someone addicted to social media.".

example
"i am a social media junky".
or
"i waste hours online on social media"
or
"i am a self-proclaimed facebook addict".