Do I have postpartum depression?

My baby is 2 weeks old. And yesterday I just got so emotional Idk what's wrong with me. I pump my milk and while I'm just sitting there pumping I'm crying my eyes out. I feel so alone and overwhelmed ( I have 3 kids 2y/o and under) I have no reason to feel this way I have an amazing loving husband who helps and is always trying to make me feel better but its just like I can't catch a break. I feel like im drowning and can't get my head above water. I felt fine until yesterday all these emotions started then. Has anybody else felt like this? I don't want to hurt myself, I'm just crying a lot for no reason and I honestly feel like a complete failure