Hello!
I don't have excellent advice to add on top of what's already been said, and I know that's a bit useless, but I just wanted to send you some love and encouragement. Newborns can be SO overwhelming, especially when they won't calm down. Do you have a kangaroo wrap? Sometimes being snuggled close in a wrap can help baby calm down while giving your arms a rest. Always remember to preserve your mental health--if you need to step out for a moment to gather yourself, place baby safely on their back in a pen or playpen and step out of the room for a moment. It sounds counter-intuitive, but crying for a minute isn't going to kill or traumatize him--and it gives you a second to breathe. I'm sorry this is so stressful for you! I hope things get better. ❤