Did anyone had to deal with a parent or a loved one that has schizophrenial/psychosis?

Lately my father has been acting irrational (compared to his normal irrationality), at first i didn't take it seriously as i took it as an old man being irrational and stubborn which is i guess common with father's as they get old, however things evolved to something i was not expecting, my father is at a stage where he thinks his monitored, he says irrational things like his being followed, stalked, there are cameras at the house, people taking pictures of him, people listening to his phone calls etc. after digging there is no proof of anything his saying, he mentions for example pictures sent to him, text messages with threats etc, but when he get asked to show them he gets confused and makes some random excuse like i lost it or its deleted. Things evolved so fast that he even pressed charges on some phone number which btw i looked into them and they have a 0 score fraud a and they were issued in another part of the country. He his also living in a constant fear, as what i described above is his reality now whcih makes sense since anyone would be scared. I would just like to hear someone's personal experience, maybe doctor's to recommend ect. Thank u in advance