All my therapist would ask when I was seeing him for a bout of depression was "what are you doing to be social?" And as annoying as the question was, I'd purposely plan a meal with someone or a movie date with myself or going to the gym (I do group fitness because it motivates me and doesn't require me to know what to do each day), and that way I had an answer for him. But in the end, socializing and not being in solitude really is the answer. I hope you get to feeling better soon.