2009 Toyota tundra electrical wiring nightmare

Hello and thank you to everyone. 2009 Toyota tundra SR5. My one license plate light was out. Someone along the way already ran additional grounds from both license plate light and tail lights to each other. I found the loose ground and left the key on so I could see the connection was good while trying to hold a light,solder and feed the solder next thing you know lights go out. I checked the fuses and rechecked the fuses. I checked the passenger compartment fuses also. Come home today get at it again and now all kinda funky things were happening. So I took off battery terminals and held positive and negative together to reset the BCM. All the funky stuff stopped and now I have no power to one half of the passenger fuse panel above emergency brake. And obviously still no parking,license plate nor fog lights. Thanks so much!