Feeling frustrated...

I hope I'm not the only one that is going completely crazy... it seems like ever since my LO was born I have been super snappy at my 5 year old (it doesn't help that she is the worst listener and is in the "why?" phase) but not only that I get stressed and or frustrated at almost everything and everyone! Idk what is wrong with me.. my LO sleeps great at night so I know it's not sleep deprivation that is making my fuse so short. I was asked if I have PPD but I don't feel sad or depressed (other than the occasional cabin fever) could this be PPD?.. I have absolutely no patience and I feel like I'm destroying my relationship with my oldest daughter :( tonight she asked me "where is my happy girl?" And "why don't you love me?" That absolutely broke my heart! Any advice or tips would be greatly appreciated! Oh and to make matters worse I have little to no help from my husband, I have asked to stay with the LO so my oldest and I can have a just us day and he avoids being left alone with the baby at all cost! He has many daddy/daughter days with just our oldest but I get none.. it doesn't seem fair. I just needed to vent a little.. 😧😭😔