I lost interest in hobbies I used to love completely

My guitar collects dust. My running shoes haven't left the closet in months. These were things that used to make me feel like myself, and now I look at them and feel nothing — or worse, sadness for who I used to be. People say 'just pick it back up' like it's that simple. I want to want to. I just don't right now. I'm worried if I wait too long, those parts of me are gone for good. Did your interests ever come back?