I don't know what to do

I think I have post partum depression. And I don't want to tell anyone cause I feel like that means I failed. Like I'm not strong enough. And it has nothing to do with my baby. I love him more than anything. I just feel so alone and stressed

I am losing my job. And I can't talk to my fiance about me being so stressed cause it will stress him out and I don't want him to be stressed out or depressed. I just feel so alone and sad all the time and I just don't know what to do.