Yes, I have felt like that. I began to wonder if I'd suddenly lost all empathy and love for everyone, even my most beloved people. I was emotionally dead. Yes, it was after a massive shock almost amounting to PTSD. However, I think the best things I did were, to seek help and to force myself to be in the company of people who helped me feel positive about myself. I'll describe what I did in the hope that just maybe it will help. Talking about it is a therapy in itself, so coming on here and telling us was a huge positive step.
I had counselling which I paid for because the waiting list was something like 3 months and I knew I didn't have that long to try to turn it around. Fortunately she was excellent. I had acupuncture twice a week at first to restore a sense of calm and wellbeing.
I tried to reward myself with some small treat for getting through a few hours without that feeling of dread. A coffee in a coffee shop with people around me although I have a wonderful coffee machine at home. I joined an art class. I forced myself to accept invitations to things even though I wanted to leave after an hour or so. I put on a cheerful telephone voice to friends so they wouldn't worry about me. It took a while, but I did it with help.
It's a horrid, empty feeling and if you don't begin to feel more positively fairly quickly I would seek help. I'd be happy to reply if you wish to PM me.