Sorry you are feeling depressed. One thing that I did after leaving was to put a moratorium on dating/relationships. No old flames, no new flings. I was the type of person who used relationships to fill the emptiness inside me and I knew that was a pattern I wanted to break.
I have filled my time with Alanon service work, writing a novel, spending time with my sons, meditation, exercise and working extra jobs. Meeting true friends in Alanon has fulfilled my need for relationships for the time being and I rarely have the time or inclination to be lonely.
Some of that is the result of breaking my old pattern, but mostly it is because I have reframed my view of "alone time" as being something to be valued and savored because I am busy and fulfilled in so many other ways.
Hugs Sally.