Uy, mama, if you're feeling this way, please talk to your doctor or go to a health center, this is important and they need to know. Hindi ka nag-iisa dito, and what you're feeling is valid.
Yes, postpartum depression can still happen even after a year, but I'm not the one to say what's really going on, only a doctor can help you figure that out properly. A few of us mums have been through rough patches way past the first months din, and the best thing we did was ask for help. You deserve to feel better, mama.