Postpartum depression?

I'm worried that I may be experiencing the beginnings of PPD. I'm clinically depressed already but I've heard this is a whole different monster. When my baby cries, I want to cry. Even just looking at her and thinking about how much I love her makes me cry. I'm not able to breastfeed at the moment so I feel hopeless about that and feel like I'm not giving her all that I could. Not sure if this is PPD or not so any help would be appreciated..