I also experienced severe depression 16 years ago when my fiancee of 7 years left me for another man. There was a massive void in my life that couldn't be filled.
I cheered myself up by exercising. Picked up kendo and hiking. Free dose of endorphins and you look better, sleep better.
Go to a cai png store, heck care the prices, choose the food that makes you happy. For me it's usually a giant steamed drumstick and two eggs with spinach. I picked up cooking and made healthy meals of the foods I liked.
Visit a library. Find one or two authors that are highly recommended. Read every single one of their books. Murakami got me through the 1 year I suffered withdrawal from not having a life partner.
Go wander around youtube or spotify. Find some inspirational videos, a new interest, discover new genres of music.
Jim Carrey has an excellent quote on depression: “I believe depression is legitimate. But I also believe that if you don't exercise, eat nutritious food, get sunlight, get enough sleep, consume positive material, surround yourself with support, then you aren't giving yourself a fighting chance.”