"My son feels offended because I went to the school and got a drug test to be performed on him. What I can do to ease the hate he now feels toward me? How can I make him talk to me again without giving him the edge?"
I don't think your son hates you. He probably doesn't like you, though. Sit down with your son and have the following conversation:
Tell him that you love him so much that you are not willing to stand by and watch him make poor choices and engage in self-destructive behaviors that will hurt him -- and his family. This is why you are using "tough love."
You're not out to make his life miserable, you are trying to help him grow. If you didn't love or care for him, you wouldn't bother with him.
Resist your impulse to strive and struggle for your son's acceptance. Don't strain to get him to "like" you as you begin to set some limits with his behavior. Instead, enjoy the process of the good parenting you are doing. His acceptance will come independent of your striving for it.
Love and caring for your son is about process, not outcome. And process is about purpose. And purpose is about doing what you know in your heart is the right thing to do whether your son sees it yet or not.
Believe it or not, one day your son will see the bigger picture and realize you were doing him a favor all along.
My Out-of-Control Teen: Help for Parents