Postpartum depression?!

I really think im depressed! I argue w ma bf non stop, and for nothing or for some little shit!, i am not that happy about me havin a second baby and i feel so bad! I will protect and watch her but i dnt feel ATTACHED like i did w my son (now 7yrs old) i feel it way different w her! Is that normal?! I think ima make an appt w my dr n talk to him about it again! I told him when i was pregnant and he said "i dnt think ur depressed, its just the changes ur going through" n im thinkin "umm No! I know my body n myself im freakin depressed, i want to sleep all day, i cry every freakin day(a couple times a day actually) i am numb as the days go by!