Feeling sadness, depression, and many other things for a long time. I want to improvement my mind.

I have been feeling sad, depressed for a very long time. overthinking stuff, can't think even straight and I speak sometimes randomly without even putting thoughts because my mind is not clear often.
I want to socialize more
smile more
be more cheerful
be more like I'm feeling human instead of feeling like empty inside
I got a therapist appointment next monday and I got a doctor.
Is it okey to force smiles and force myself to do other things like talk more, be more cheerful? Im not organized and I depend on people.
I loose interest in things so fast. It's hard to live with a mental exhaustion brain.
I don't know how to start.

 

First sentence is the effect. 2nd sentence is the root cause. The rest falls into place when you tackle these. Your mind is like a 6th sense. I mean this very literally. You seem to believe you are that voice in your head, and it causes all suffering. Sooner you accept this the sooner life changes dramatically. Find your way through the forest of doubt your mind throws at you as you try to digest it. Deep down you know it’s fact.

 

I found a fantastic post you made awhile ago. Perhaps you need to revisit Clairs Weekes:
https://www.tmswiki.org/forum/threads/ocd-perfectionism-and-tms.22281/ (OCD, perfectionism and TMS)