Just looked at that origianl log... ugh... lots of issues. and the device error may be causing CPU issues causing streaming/connection issues
real-time hardware resource monitoring (Task Manager and related Performance/Resource Monitor need to become tools you are familiar with) when using under-powered computer and trying to make the most of it.
1. run though OBS's Analyzer (see my .sig for link)
2. 10 generation old CPU... and you are CPU re-scaling video
if stuck using that PC, maybe an older NVENC capable GPU to do some encoding offload... but really, that PC too old to spend money on and be a good value choice. I would however, check if someone has an old nVidia GPU, matching PCIe bus, with NVENC you could test with. Doing so will require how to adjust OBS Studio settings appropriately.
3. you have mismatched audio sampling rates, especially bad idea on under-powered hardware. If you can't change Audio sampling rate on camera, then change everything on PC to match camera. Disable Audio on devices where you don't intend to use Audio
4. Why 48fps for house of worship livestream? especially on under-powered hardware
As Facebook changed to allow general 1080p streaming, I'd be inclined to test 1080p (not 720) streaming (at 24/25/30 fps, as appropriate for your region)
5. log has
12:51:01.959: DShow: Run failed (0x800705AA): Insufficient system resources exist to complete the requested service.
after trying to start 2nd camera... followed by nothing but errors which can itself cause other problems (maybe/depends)