I know I am late to the party but hey I made a person of my own and she arrived early on 9/4. Could it simply be sleep regression? I know it happens around 4 months (and some other times). The sleep thing is tricky and I second the idea of avoiding the blogs. They are full of keyboard warriors parroting advice they heard that worked for one mom they saw in an insta vid. I encouraged my wife to abandon them ASAP as she was starting to stress out reading all the things. SIDS is scary but as long as you are vigilant you can avoid the big issues. We let Everly nap in the swing but we are always in the room making sure she is not slumped over. Ours also reclines a fair bit to avoid the positional asphyxiation you hear about. Hang in there. It will get better.