Inner critic

I'm answering this question as if it were a question asked by myself when I was a young adult. I am assuming many things since I don't know you but I don't think what I went through was terribly extraordinary. I didn't feel there was another person inside me but I was familiar with a separate voice within my head. My assumption is that you are dealing with something similar.
I believe you are suffering from depression most likely. That voice is actively against the normal state of wanting to be alive. The voice is unnatural in that it is anti-existance. As it wishes you to not exist, it will also cease to exist with you. It’s utter and complete bullshit.
The voice is a huge liar. It probably has loads of arguments against your worth and value on this planet. It probably never shuts up. You probably even believe it now. It probably runs your life.
The good news is, you can shut it up, unarm it, and live a fabulously rich, rewarding, and successful life. The kind of life where you like yourself and aren't demanding perfection anymore.
Having serious thoughts of hurting yourself is a huge red flag to find an effective therapist to begin understanding this voice so you can take control back and learn how to love and accept yourself. Through your therapist, you might find that you need the assistance of a psychiatrist and meds for a bit to get your feet on stable ground.
-- Pamela Robertson, quora.com"4 y" | (58) Why do I feel as if there’s another person living inside of me and that makes me hurt myself? - Quora
----Multiple-person; internal persons; introjects; introject self; mindshare
headmate; self-talk; self-understanding
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