Postpartum depression

The last week or so has been increasingly difficult. Seems like the more days go by the worse my depression and the negative thoughts get.

My fiancée has been home because he has summers off due to being a teacher. And I am so terrified for when he goes back to school next week. Being alone with our baby is not something I'm looking forward to when I feel the way I do.

Anyone else going through this? What can I do to not be so depressed?