What should I do about the continuous lie I told my parents concerning a fictitious job opportunity, and the hopes and expectations that arose from it, and how can I repent from lying while I am trapped in this situation?

Lying is a great crime and one of the major sins. A believer is not naturally inclined to it. You have done well by repenting from lying in general, and this includes lying to your parents. One who repents with a general repentance has their repentance cover all sins, even if they do not specifically recall them. If you have not yet repented for lying to your parents, you can repent now, and it is obligatory upon you to make a sincere repentance. Do not let their psychological state or their aspirations prevent you from repenting or cause you to fall into lying again. If they ask you about work, use tawriyah (allusory speech).