Postpartum depression? Input please

Im a little over 3 weeks postpartum. Iv been feeling so irritable and i just want to cry at the same time. Everything is bothering me, When im around other people it feels like they are nails on a chalk board, thats the best i can describe it. Iv been yelling at my 6 yr old more too and i feel bad about it she's really not that bad either. I cant "feel" happy. I should feel happy because having another baby was a dream come true , since it took over 2 years to convince my husband for another and a year with a miscarriage to get pregnant... and here i am losing my mind. I am so in love with my baby, but i just cant get over this depressed and angry mood. I hate it and hate myself for it. I dont go to the doctors for another 3 weeks. Should i just see if i feel better or i mean , what will they do for me if i do have postpartum depression? 😢 ty