My 5-year-old daughter caught us having sex. Since then, I have somehow become very paranoid in having sex out of the fear that she will see us again. How do I get this out of my head?

dont worry so much, she is 5 and will soon forget about it. in fact, i am sure she forgot about it the same day itself, but of course you were too worried so thought she understood it all. a 5 year old is too young to understand this, so don't bring up the topic. next time be careful and put on the latch.