Years ago I read a magazine article that said there are five things you need to do to live a happy life. I wrote it down and gradually worked it into my life and, for something that came out of a probably trite magazine piece it only bloody works.
They are
Embrace change
Avoid introspection (not any introspection, but constantly living inside your own thoughts)
Be a leaf on a tree (be connected, make friends, see loved ones, join things)
Develop a passion (throw yourself into something that excites you enough to make you get up early to do more of it)
Live now.
I read the article when I was about your age and feeling meh, lost, fearful, like I didn't know what would come next and how I could be arsed with it.
My best friend had just died suddenly leaving two small children.
I thought the lights had been turned off in my life.
Since then I've lost more people (including all my aunts, uncles and parents), I've aged, I don't look like I did, everything has changed beyond all recognition.
New things have flooded in. New passions (one of which became a new career), an old hobby became another source of interest and income, volunteering in an area I really care about, a new home, a new location, new friends, new skills, a new way of looking at me and the world.
I am happier now, more fulfilled, more comfortable in my own skin than I ever was before. To be honest, my life is so full, so full of opportunity I wish I had more time and more energy. I feel on fire and free like I never have before.
I'm in my sixties.
Work consciously through this OP. This is your chance to shed shit that doesn't work for you and let new stuff in. If you do this the future will be better, you will be better than you could ever have imagined possible.