Yeah, you said it's like your organic self was frozen in some other dimension while the rest of you went on living. I know someone who says that he feels 'dead inside,' and he describes it as though some part of his soul actually died, permanently, something spiritual. He says he has no emotions at all, except remorse. It was after he went on several psychiatric drugs. I've tried to explain to him that I'm sure this feeling is happening because of the drugs, but... it's a hard subject to talk about.
There are websites where people talk about their struggles to quit using psychiatric meds, and how in some ways after they quit, they do 'wake up' again, but in other ways, sometimes the effects of the drugs linger for a very long time. I myself have some unusual theories for why the effects linger after they quit the drugs, based on my own experiences. But it could possibly permanently alter people's nerves and brains too, in some way.
It's really sad because the drugs make people unable to feel their subtle senses and subtle emotions. Sure, they help a person get through the day. I have chronic fatigue, and I use lots of caffeine, and even something as ordinary as caffeine makes me less aware of my own emotions and their nuances.
Those subtle effects actually matter. They are important. Doctors, and a lot of people, behave as though 'Everything Is Fine' so long as your arms aren't ripped off, you're not coughing up a lung, there's no visible blood, outwardly your physical body looks normal. They see only an external physical object, and the external physical object looks fine, and therefore there's nothing to worry about. The physical object of your body is still walking and talking, so there's nothing left to fix, they say. If you try to tell them that you're feeling some sensation you don't like, that's just a 'first world problem' (as you said above earlier in the thread). Doctors can fix a broken leg, but they don't know how to fix weird internal sensations that you don't like, and they don't give much priority to fixing those things, and they just ignore you if you tell them. (That's my experience.) Or they argue and tell you that you're imagining it, that it's hypochondria.
I'm glad you didn't have severe withdrawal from Sertraline when you went off it.
People have depression for a lot of reasons (and anxiety, and other mental/emotional phenomena). Nowadays everyone just tells you to take a pill so that you can force yourself to keep going, without solving the original problems. An unknown something caused your body to get depressed/anxious/tired in the first place. It's possible to find the cause and remove it so the depression/anxiety stops happening, without pills.