Sometimes, hurting is the only way. Nobody wants to hurt people, but sometimes we have to. Being truthful is going to help you in the long run. I must have missed what you did that will hurt him so bad other than you lying about you not being allowed to date?
I know if a guy I liked a lot said he wasn't allowed to date but in 6 months he could, I would have no problem with it, it would just show he liked me enough that he didn't want to wait to date. (Not that I promote that, I would've rather him told me he couldn't date.) It's not that big of a deal.
And if you are truthful, and he waits, you're not going to never see him again. You're almost graduated, you can move out and go to college, your parents can't control you your whole life, you'll always see him again.