not sure how to help you other than to recommend doing a factory reset, changing your passwords and setting up 2-step verification on all accounts where possible.....that is if you are truly hacked.
hacking is not as simple as it used to be. it is much harder to do. someone can't just access your phone that easily. you or someone would have to download and install an application for remote access. so unless you handed the phone to somebody unsupervised, i doubt it is hacked.
now after a factory reset make sure that you are not installing all of the same apps you previously had. some apps do come with malware mostly in the form of adware. but there can be other malicious malware that can be installed as well.
everything on your phone is set up as applications and every process has an app associated with it......so 500 system apps is not surprising.
i can't explain all of the other stuff you posted. if the police are not alarmed, i would pay no heed to everything else.
i am truly sorry you lost your job. and i hope you have not completely lost your mind yet....lol
i'm no shrink, but i think talking this out with a professional might help your state of mind. i'm not saying you are crazy or that i do not believe you. i'm just saying that it helps if you have someone professional to talk to. i'm a big advocate of taking care of your mental health. i just started using
Better Help. it is not free, but well worth it.