I honestly am so saddened to hear that you feel so deadened already and don't feel the spark of joy every morning on waking up and in thinking about all the joys, fun and challenges in the day ahead.
I literally wake up with an endorphins surge ( can actually feel it in my joints, like a warm excitement for the day ahead).
Rather than try and diagnose I will let you know what I do which I hope might help?
I place emphasis on eating nutritiously after finding out about the gut biome and the connection between good mood and what you eat ( lots of interesting recent research in this area).
I have recently added 5g creatine daily which is a protein commonly used for bodybuilding but has surprised me by giving me a positive energy boost. Other dietary tweaks are activated nut and seeds, oily fish, pickles, inulin and matcha green tea.
Living in a very aesthetic environment, having cute pets, all my spaces are considered and beautiful and I was able to do this without spending a lot of money.
Being kind to others, saying kind things, smiling in the mirror when I don't feel like it just to poke fun at myself but never at others.
Making things, helping others, reading widely, learning from YouTube videos, always having something to look forward to no matter how small.
Going out of my comfort zone, laughing when things don't go according to plan, laughing at myself for trying things I am hopeless at but not giving up.
Going for walks and researching the Koran and the Bible, Taoism, Buddhism etc for inspiration and being open minded and curious about the world we live in.
Asking the how? Why? And not getting too introspective as that to me is very self indulgent, self centred and boring.
Finding out about critical race theory, unconscious bias, reading the history and biographies of inspiring people who have made a difference.
How about making a positive difference to someone else's life instead of being so self consumed all the time?
Life is a wonderful, a beautiful tapestry of interesting people, cultures, animals and landscapes.
I am so saddened you don't see it. But there is hope yet!