Scared of getting caught doing something wrong?

I used to be paranoid of what my parents would catch me doing when I used or love at home . That extended to teachers and classmates when I went to a school where most of the people were assholes. I cannot sit in front of a computer without being terieifed of who is looking at my screen. I am not even used to keeping the computer in a comfortable position coz my parents used to come busting in my room to catch me doing stuff. .... Like watching movies or porn. Still terrified when the picture of a girl pops up on my phone.