The car is an 08 Is350. About 3 weeks ago, the car would crank but not start. After changing the fuel pump that issue went away. A few days after the fuel pump was changed I hit an extremely small pot hole & I had to push it into a parking lot because it wouldn’t accelerate. While waiting for a tow in the parking lot I turned the car off but when I tried to turn it back on, nothing. No electrical power whatsoever & no power steering either. I checked alternator & battery, both are fine. Really unsure what the issue here is but I desperately want my car back on the road. After searching some forums, power source ECU may be the culprit but it’s an expensive part that I don’t want to incorrectly purchase. Does anyone have any tips? Thinking about just giving up & taking it to a dealership after some certified Lexus technicians couldn’t figure out the issue

edit: FYI, I realized the fuel pump was messed up because the car wasn’t holding power while in idle & while driving I couldn’t go past 3500 RPMS