Turn around and look forwards, not backwards. Get out of your own head and into what is happening all around you. It's never too late to change, it just gets harder if you have been in the habit of lying/cheating, you have to replace that with double the not lying/cheating so you get a new, more comfortable habit.

A dictionary is not worth all this angst and you told him you took it so let it go. If it makes you feel better, invent a program to get dictionaries for school teachers or something:

Dictionaries for All