What do you do when you feel so very unappreciated?

My partner has 2 developementally delayed girls ages 11 and 12. I have been with him for 3 years with the exception of the 5 months I couldn't take it anymore and went back to my family in California. I do everything for them to help them acheive higher standards than what was expected of them when I met their father. I teach them how to say pillow and not pidow, etc, as I have observed them each very carefully and know that they can do much more than anyone seemed to be teaching them. They both get SSI/SSD and he does not work. They go to school and one of them is in special cles, but they are gone all day. I cook, clean and prepare the entire house for their coming home as they are quite demanding of me. They are not so demanding of their father as they feel the answers will be no, or they will be told to do it themselves with no monitoring of the mess that they create. He does not work outside of the home and pretty much lays down all day and watches TV. On occasion he cooks dinner and does a load of laundry that he has to be reminded to put in the dryer and take out. When the school calls, he says he is the one who helps them with homework, he is the one who has noticed or observed things about them, and all along it is me. I tell him things about them and other things and he acts always like it was him. He calls people and says things like I am cooking dinner and gets a oh you are so special from his female crack head friend. Well considering I do this day in and day out and not frozen food, homemade tamales, enchiladas, chinese food, whatever he wants, aren't I special? It all just seems to go unnoticed and unappreciated. And the meal he may cook, he talks about how wonderful it was and expects us all to rant and rave for the entire night about it. What the heck is going on here? What do I do, I tried to tell him and he shuns it all off.