Is this post partum depression?

My daughter is 9 months old. I haven’t noticed very much ppd but I have noticed a TON of uncontrollable pp anxiety. Lately when she’s down for a nap and I finally have a quiet minute alone, I cry. I cry for no reason, I cry over any tiny thing I see on the tv or on social media. Anything at all whether it’s sad or happy. I don’t understand why..