2005 Odyssey shudders while braking and electrical issues after brake change

Hello, all, I have just replaced the brake pads and rotors on my dad's car, and it went well. We tried to drive the car around the block with no issues and tested braking, that was fine too. But, when we got home, the dashboard lit up like a Christmas tree with all sorts of problems (Airbag system, charging system malfunction, abs). After that, the car was very weak with accelerating and when braking at speed. It would shudder and the interior lights would flicker as well, and the infotainment has no sound as well.

This car has some electrical issues, but we replaced the wiring system because there were corroded spots that stopped getting good electrical connection. The alternator was replaced a couple years ago, and no one thinks that's the problem.

I changed the brakes and the rotors, but bled the brakes since one of the brake pistons popped out and I had to reinsert it inside the caliper. What do I do now?