how do i stop having paranoid/anxious thoughts and be able to distinguish realistic vs not. 

i dont know if this is the right place to post, but almost always I've have paranoid thoughts about someone watching and or killing me/family for a long time and it stops me from doing things and sometimes the people around me too. From me stopping them in fear of them getting hurt. i dont want to be like that and panic cry when they leave because I think theyre in danger or something. Staying home alone is terrifying cause someone might break in and kill me, going out I think there might be a bomber or a shooting, thinking theres cameras in my house/room, someone outside my house watching me, scared of people online/in person, all these thoughts ive had. I dont even watch true crime stuff or the news to induce these to me. Ngl even just posting this scares me. It causes me great stress. Are these irrational or normal? how do i stop them?...