Have you had such similar paranoid thoughts before?
I get like that when I'm very very stressed and very very low....There have been times I've been searching my room for cameras or being terrified to send emails because I'm convinced someone monitors them and somehow I'll get in trouble because of...I don't know what.

I don't have any pearls of wisdom for this..Just keep reminding yourself that these thoughts are irrational. Being in touch with people helps me sometimes. The calm presence of others can help you feel less like everyone is out to get you...Also, doing your schoolwork is good but maybe switch to different things every few hours? I find that doing one thing for too long (or trying to anyway) can make things worse (as I get more frustrated with my own perfectionism, especially if I'm not well, therefore I can't do anything at the best of my ability....be it cleaning, work, or whatever..)

Also...remember that whatever can plausibly have gone wrong...e.g. forgotten to do something for school...it can easily be rectified It seems to me you just need reassurance for things at the moment..