You speak of his "knowing" the lying hurts you, but it may be hard for you to really get it that his lying is not about you. If you make it about you (and of course it's normal to feel like it is) then it's not safe for him to tell the truth. You may want to take a look at some of the literature about growing up in dysfunctional families (one example of a place you can get that is adultchildren.org). One of the biggest tells that a person was raised in an environment of "don't talk, don't trust, don't feel" is that they "lie when it would be just as easy to tell the truth." This has to do with their earliest experiences and how telling the truth was not a positive way forward. It's not enough to say, "I hate lying." He has to experience over a period of time that it's safer to tell the truth than to lie. Part of safety is a stable home, where you know the rug won't be pulled out under you. You've been trying to give him that, and you need him to do his part to create safety (emotional and otherwise) in the home. This is not a self-help issue or an issue of "discipline." A combination of an Alateen group or therapy group with good counselor for adolescents would be ideal and provide you with support you need and deserve.