Hi guys, I am experiencing the weirdest problems with my car and I need some help diagnosing. I drive a 1998 Lexus GS400.

About 2 months ago my car starts making this weird humming sound when I start it and drive it but it didn’t seem to affect anything, the more I accelerated the more sound it would make. The next day my car would not start; wouldn’t crank or lights nothing. A guy from AAA came and replaced the terminals and the car started fine but would idle too low then it would turn off because the low idle. I got it towed and the mechanic cleaned the the throttle body and it ran good after that, but it would still make the weird humming sound and now the vcs abs and vcs off lights were on. I left and didn’t touch the car for a month, and when I came back to start it it was completely dead again. I got it jumped, but everytime I junior it it doesn’t hold its power and it sputters out and dies again. The alternator battery and starter were tested and were running perfectly fine according to. AAA. I have no clue what to do now. Help Please! Thank you !