Nothing feels enjoyable anymore and I don't know why

I used to love cooking on Sundays and going for walks. Now I stare at the ingredients and feel nothing. I still do the things sometimes, but it's like watching someone else's life. Friends invite me out and I say yes because I should want to go, then spend the whole time waiting to leave. I'm not actively sad every moment — mostly just flat. Like the color got turned down on everything. Did enjoyment come back for you, or did you find something else?