That was how I felt a couple of years ago, even after I beat my depression.
I could only describe the feeling as existential rot.
My family members had all been dead for a couple of years, I was stuck in a job I hated, I didn't have a vision of where I wanted to go with my life, no wife or gf... the only ones who cared about me were a cat and a bunch of bill collectors. Felt lousy, like a slow, inexorabe decline in my quality of life.
Then a close friend who I've known for over 30 years (and s also on the spectrum) was just about ready to crash.
He had been married to a narcissist for 10 years, she was making him physically ill, and he was suicidal. I talked hm back from the edge and convinced him to get a divorce. He had to be taught to live again. In return, he taught me that I shouldn't give up on my projects.
Now, a couple of years later, I still struggle with an inability to feel pleasure from "fun" activities because of my past battles with depression, but my life has direction. I've started a new job that I actually like, I've rekindled my interest in a couple of my old hobbies, and my friend has begun rebuilding his life by also getting a new job and revisiting some of his old hobbies.
So yes, it sucks seeing the world through a blue haze... but you CAN bootstrap.