Screaming 7-month-old baby

I really feel you on this, it can be so startling and worrying when they do that piercing screech out of nowhere. My girl went through the exact same phase around that age and I remember googling at 2am thinking something was wrong, but it turned out she was just discovering her own voice and testing what it could do. For the frustration screaming, I found that narrating what she was feeling out loud, like saying "I know you want to reach that toy, I hear you," helped her feel understood and sometimes calmed her down faster than I expected. If you are still worried about his throat or it seems to be causing him pain, it is worth a quick check with your PD just for peace of mind lah.