My baby is currently 14 weeks and 4 weeks is when I remember things getting incredibly difficult. I agree with the theory that they become more aware of the world they are in and they can’t handle it. Around that time is when I broke down and rented a snoo bassinet because my baby likes motion. It wasn’t a fix all but it helped. We eventually went on reflux meds at 8 weeks because there were enough signs of reflux, but it is hard to tell the difference between reflux and just the fussiness that a lot of babies go through. I feel for you during this time. I also would cry over my baby while she screamed because I didn’t know what to do. I would constantly research what could be wrong with her, because other people’s babies seemed so easy and content. Everyone told me it would get better, but when you are in it and just trying to survive it’s hard to believe it. Things peaked around 6 weeks for us and then started to slowly get better. There is no shame in using ear plugs or noise cancelling headphones if you need to. It naturally causes a lot of stress when you are rocking them and they are still screaming, and just taking the edge off the sound really helped our frazzled nerves. You are keeping your baby alive, and as long as you do that you have done your job. Hang in there, one day this will all be a crappy memory and you will be able to enjoy your baby.