I am so ready to die.

I have nothing going for me. I am so completely isolated. My wife is so completely clueless. I can't stand my adult kids. My teenagers are old enough now that they don't need me. I barely see them. My problems are so overwhelming but everyone around me just goes out of their way to avoid talking about anything constructive. There is nothing better in my future.

Every problem you listed can be changed. Instead of giving up, try something else. Try something new. There is a lot in the world that is better, so go find it. If you aren't happy, change the situation. If your wife is clueless, make her understand or move on from her. Your kids will always need you, whether they think they do or not. You are their parent, find a way to strengthen those relationships. Find something to do away from them. There is so much in this world that is good, don't give up on it and don't give up on your kids.

There is something for sure, there must be. I have the same thoughts, and i'm only 23 but you shouldn't give up. Read a book saga, it often helps me to not feeling abbandoned. The feeling that a new chapter is awaiting you helped me throught my life

Do you really want to die just because your family is treating you this way? I'm not saying that your situation isn't as bad as you think it is. I don't know your life. But it seems to me that you're placing too much value on how they think of you, and not enough on yourself. I've thought this way before, to be honest, that if everyone else would rather not be around me then maybe I should just get on with it. But I also felt like that was giving them too much power. Why did I care more about them (those people that could so easily dismiss their own family as nothing) than I did my own life?
I decided to try and care more about myself, to take up my time with things I was interested in to get my mind off my problems. (Unix's reading idea is great. I wouldn't limit it to just a series though.) I also started working through some of my problems (health, debt, job change, etc.) and though nothing is actually fixed yet, I do feel better about myself because of the effort I've put in and the small (though still measurable) progress I've made. Not really better about my family, but they are always going to be that way - you can't change others.
If you have no one to talk to, I'm guessing you're talking about your family, try some one else. Some one unbiased, outside of your problem. There's a whole forum full of people on here that would be happy to help out with advice, if asked. If you feel you would benefit from therapy, I would give it try.
Don't be in such a hurry to die. Life is short, spend it the way you want and don't let other people ruin it for you.