OP I have been where you are. I know that terrible feeling. You can speak out here and most people are very supportive.
In terms of what to do next...be kind to yourself. Talk to your husband, rant, scream, cry, take to bed or go for a walk. Whatever will help.
Try to eat and take care of your physical self. I know it's hard when you are so down. I have two toddlers and a full time job, I just felt like my life was pointless. That I was a non-entity. But I'm slowly clawing my way back up.
Are you on any meds, have you had them changed or a dosage tweaked lately. I know that can be a trigger for me.
You could try mindfulness, Headspace app is free for 10 sessions.
Have you had counselling before?
Tell us more about yourself, we might be able to help, even if it's just a hand hold in dark times.
Hugs to you, you can get through this.