Addictive behavior always seems to carry with it lies, lies and more lies. TV addiction is a way of avoiding personal contact and a vicarious way of "managing" ones own life. His summer job teaching children is more of the same. He got a lot more strokes out of that than mowing lawns and the physical things that many teens do to make their own spending money and achieve a feeling of independence.
Yes, I agree with some of the posters that you have screwed up on the parenting front and probably as a husband, too. That's not the point here. All things are relative and our sins and slippages have a way of balancing out when they are in a healthy relationship. What we don't have, our wife does, so to speak. In effect the two are equal to three when together. That's a nice form of complementarity. Sounds like it didn't work out too well for you.
You can reestablish your position and live a good life with her, but you can't do it and continue to be a wuss! The rest of my comments stand. You can muddle around and find yourself doing the same old things again or make a change.