Mixed emotions. Why is this happening?

[M.Tesla]

I'm having very mixed feelings about this life- in its totality.

I simultaneously feel... grief for the ones that are gone forever, or have changed into another person entirely- missing their ghost; nostalgia for this life feeling the future of myself as passed away longing for this life, the people I've formed bonds with, longing for the feelings I've experienced, longing for my home which I came from. I was born into this earth, and my astral birth (possibly death) date is july 14, 2008 - I changed that day. I felt another soul intertwined with my own in space, time disappeared; I remember my previous (before 7/14/08) views on life and they're entirely different to who I am today. I used to be a bright, passionate, deeply loving, thoughtful, and wise person. It all changed. I became very dark and pessimistic after feeling that soul waved with mine, and the way I felt that soul leaving me hurt deeply. My issue is I still dont know what I'm to do. I can either leave the past behind, delve into my darkness, and hope that by going into the darkness I will cure myself. Optionally instead of that I can try to bring back my previous self? I've been attempting that for years. No luck. I MISS THAT PLACE SO MUCH!! it was like... nothing was wrong, there wasnt a single negative emotion inside of me. Everything, was beautiful. Peaceful. So peaceful.

Honestly how do I get this back? Is it a long hard road to being ok or can it be instant?