Give up social media (all of it: Twitter, Reddit, Facebook, HN), porn, and TV (including Netflix) for a couple of months. Take up some form of exercise (lifting, running, even pilates or something), and re-evaluate your attention span.
I'm not being flippant. If your therapist hasn't recommended this as at least a starting point to better diagnose you, then you need a better therapist.
Whenever a friend tells me they're depressed, or anxious, or have attention difficulties or whatever, the first thing I ask is "what did you spend most of your time doing last week?". If the answer is "Oh, I found this cool new show and binged it", or "Oh not much, I wasn't motivated to do anything so mostly just scrolling the feed haha" - I immediately sit them down and suggest that maybe those things are the cause and not the symptoms. You aren't depressed, therefore you watch TV and observe other people's lives on Instagram. You are depressed because you do those things with the majority of your waking hours.
Sure, many people suffer from depression, anxiety, etc. for plenty of other reasons they cannot control. But the rates of this in Western countries are skyrocketing. There has to be a better reason for that than "it's just who I am".