Absolutely go and see IL's. You need H to see that you really do care for HIS side of the family too. Vent to us and NEVER to him about his own family. I learned that the hard way. I am STILL trying to show H that I love his family. (Maybe not as much as my own, but he doesn't need to know that. )
Continue acting as if.
The burden of having the kids all the time does wear on you. A long time ago H said something to me about me not seeing how important his work was. Not taking him seriously. For instance, when H would be in the office working. (computer job) I would ask H for help bathing the kids. Now I don't feel that is asking too much, but H would see it as, "don't you see that I am busy...."