It's been 2 days, I disconnected the terminals on that day. And I was free today to connected those and there was one fuse which looked a bit off so I took it out and places it again, then started the car, it started normally without any error. And now I have that fear that it can show errors and go bad at any moment without any reason.
Still went to an electrician but he was like there's no error right now. Bring it when you face those errors. As for the precautions, bought extra fuses and a battery pawerbank. What's your suggestion? Showed the car to electrician but he wasn't able to find any error coz car was working fine.
Attaching fuse box pic below.