Feeling like a bad mom

Anybody feel like a bad mom sometimes for getting frustrated when you baby wont stop crying or sleep, even after you have taken care of all their needs? Or will only calm when you walk them around the house? I get so frustrated with my baby end up putting them in their swing or crying with them. I have even gotten to the point where I dont yell, but just say "ok I cant handle this you are going into your swing," or asking them why they wont sleep or what in the world is wrong? its only been occasionally up until recently at 4 months where they have to be held nearly 24/7 and will not fall asleep easily anymore. Am I suffering ppd, a bad mom or is this normal? Please understand I will never harm my baby as I love my child more than anything and this baby is our miracle as we have had a few miscarriages. I have spoiled them a bit by not putting them down and always having them near me when I do. Is it just starting to get to be too much?