I flinch every time my parents walk by

For context, to avoid snap decisions, read this. I (16f) am used to knowing exactly where my parents are at all times. I do things they do not approve of, for example, play video games and for this reason I usually know where they are so I can hide it by alt tabbing. My parents are very critical of me and I am almost always in the wrong for something, usually it is something I could fix, like put dishes away or pick something up off the floor. For this reason, I usually don't enjoy confrontations with my parents. My parents put my desk in the middle of the house so they can see what I'm doing (not playing video games). I spend little time away from them or in my room(my mom is always home). Lately, though, I've been really jumpy whenever my parents walk past my room or anywhere where I'm clearly not working. For example, when I'm getting ice cream (something they will criticize me for eating b/c I said I wanted to eat more healthy). I also flinch when they walk past my room when I'm just standing there and not being productive doing work or chores because apparently I'm not getting enough work done during the summer. I'm worried my behaviour isn't normal and my parents are wearing on my mental health and sanity.