Successful people don't work harder. They work smarter.
What works? What doesn't?
At what point do you throw in the towel?
A better question.. if getting beaten up in a boxing ring isn't working.. why not change the venue?
Being together for the kids is the glue that binds while you and your wife rebuild the foundation. The love of your children works for both of you. Being a martyr or lacking responsibilities in a marriage doesn't. Define your priorities, goals.. get help... learn to accomplish them in a healthy way.
Time to start reading... "How to Make Your Marriage Work without Talking", "CoDependent No More", "His Needs, Her Needs", "The Four Agreements", "Hold On To Your N.U.T.S".
Google Retrouvaille and read up on that. It is highly recommended and might be worth considering.
No one deserves to be in an unloving relationship, living a life of anger, withdrawal and bitterness. And this goes TWO ways.
It's alright to feel icky. The good news is that you can work smarter... get healthy in mind body and spirit. The rest will follow.