Yes, Kninjanin, this worldwide "phenomenon" has been observed since a certain number of years; so many people want to share pictures, music, opinions, videos, travels, sports, fun, experiences, family, friends, pets, happy and sad moments - as good as everything in their life - on-line; it is like an addiction, a quest for recognition and for collecting thousands of friends.
I hope that Dan can give you a useful idea about how to disconnect from unwanted apps or sites and reduce the number of messages.
Personally, I realised very quickly that I couldn't follow up with messsages, and I had to ask them to be patient, as I often kept them waiting.
Go at your rhythm - real friends will understand and keep in touch, at your rhythm, and many others will probably find you too slow or boring and forget about you ... And reduce the number and the time spent with on-line or video games.
After all, the quality is much more important than the number.