Stressed and Tired of it all!

I am married. I have three children. Aleczander is 5, Donovan will be 4 next week and Alison is 1. I am active duty navy and my husband is a complete ass! Our 4 year son has under gone 4 open heart surgeries, a stroke and a heart transplant in December of 2006. I sat in the hospital with my son and my (then) 10 week old daughter while he sat at home with our 5 year old son. I did it by myself. He stays at home with the children while I work full time. I do all of the cooking, all of the cleaning, all of the shopping, all of the laundry. I book all of Donovan's appointments and I take Donovan to all of his appointments by myself! BY MYSELF being the key words here! Not to mention that I go to school full time!!!! My husband? He sets on the couch and lets the children destroy my house while I am at work. I come home and and have to do it all over again. I am exhausted all of the time and he is angry at me for it all of the time. It got much worse this past Christmas! We went to Missouri to see my family for two weeks! I have not seen my family in three years. I have not been home for Christmas in 5 years! The entire time that we were there, he started a fight with me at least once a day. He told me that he hates our 1 year old daughter. He did everything that he could to alienate me from my family for the two weeks. On Christmas day, he started a fight with me over bacon for breakfast. Started a fight with me over something that had happened while I was in the shower (because I have control over what happens while I am in the shower). The day proceeded with him screaming at my 5 year old niece, throwing a plate of food on the play room floor, calling my grandmother a (don't know if I can use the word here so...)rymes with witch, yelled at my mother, told me infront of my entire family that I was a horrible wife. We are home now and have been for a couple of days and he is acting like nothing happened at all! But I just can't shake this! I think that I have finally had it with him. (By the way, this is only the tip of the ice berg. He acts like this every time that we are around my family. The last time that my mother came of PA, he threatened to throw my children out of a window. I had to have my Chief watch my children while I took my mom back to the air port). No matter how much he apologizes and tries to make up for it, I can't shake it. I think that I have hit the end of my rope. I think that I am ready for a divorce, but how do I know for sure? How do I know if this is what is right for my children?