Tired of this emotional rollercoaster

Me and my wife have been married now for seven years. We dated in high school for about a year before splitting. Both dated other people before getting back together three years later. We thought that finding ourselves once again was a sign that we were meant to be. We have quickly figured out that we are still the same couple that just couldn't seem to get it together. Always right back to square one with all the fighting and arguing! Thing is in between the fights and throwing the big "D" word around we managed to have three beautiful children. Kids we both love and cherish very much. Which is pretty much what has kept us from tearing each other apart. And that is my problem!! Our fighting and arguing has gotten so bad these days its starting to affect the kids. They are still fairly young (6,3, 1 1/2) two boys and girl. I notice the affects in the oldest one the most. He jokes around and laughs that mommy and daddy fight to much and how he wishes he could trade us in on other parents. And to him its just a funny joke and nothing more. He is use to it, thats just what mommy's and daddy's do. We yell, scream, cuss, and sometimes throw things. I have sat my wife down and explain to her the negative affects this is having and how if we keep it up we are going to ruine our children. And she agree's untill the next day when something she doesn't like happens, or if I qustion something i shouldn't have and she blows up flying the 'F' word all over the kitchen, and when I tell her to take it outside or in another room cause the kids are right there, she says she just doesn't give a 'F'. And this is just the tip of the ice burge for us. Every fight and arguement leads to one final ending statement that we just done. Neither one can take it anymore. The love and respect is no longer there. The communication is horrible and what little sex we have is about five minutes a week. After we have brushed or teeth and in between Grey's Anotomy and Private Practice! There is much more, I don't want to write my whole life story in one complaint. Anyone reading this, i would appreciate an outside perspective from someone other than a friend or family member. Thanks