I quit school for about 6months now and I continue tell my boyfriend I'm still going to school,and now I want to tell him the truth. Even though I believe that the mistake of a love one shouldn't change anything,I still don't know how to tell him after his project.

What kept you from going? Is he in a different school? How old are the 2 of you?

You tell him you are sorry but you've been dishonest. That you have quit school. What happens will happen. There is always a price to be paid for lying.
How old are the two of you