Can you experience postpartum depression up to 9 mos after giving birth?

I had a c- section to deliver my son and I became ill after and wasn't felling myself for about 3 mos. Also I went through a lot of hardships soon after. My son is now 9 months and I feel really depressed, perhaps I have a little the whole time, but now it seems to be unbearable. I feel like driving far away, but most of the time I stay in my room in the dark and sleep sometimes cry. Could this possibly be postpartum depression?