My Wife is an Alien and its killing me...

[MrBond]

"My question is: How do I find the strength to keep on fighting and struggling for someone who isn't even appealing to me any more?"

By not fighting and struggling.

Is this where I find detachment and truly only work for myself and my kids?"

You should have already been doing this. You dictate the changes in yourself on your own. You don't look to your W to validate those changes for you.

"I'm at a crossroads. I am having a hard time even looking at her and being friendly at this point."

Then detach. You don't need to do it with hate or anger. You just let her live her own life and you live yours. It isn't easy at first but it will get better.