Postpartum depression or something else

I’m not sure what it is but I get a wave of sadness from time to time, I want to be left alone, I feel the need to cry. Idk if you can get post partum depression a year and a half after having your baby. To make it worse his dad says why are you just in the dark alone or you’ve been moody all day. That doesn’t help with how I feel n then I just cry. I feeel so bad cuz I have my baby but sometimes I just want to be alone or I think maybe it’s better I leave this life. Idk what it is. Ppd? Depression? Hormones are not right? Period? This sucks..