How can I make my exhausting and hectic evening dinner routine pleasant?

I'm a working mother of twins. My husband and I get up at 4:30 every morning to get ready to go to work. We both have to be out of the door at 6:00am. We both work all day and are exhausted when we get home. I get home with the twins a little bit before my husband around 5pm. As soon as I get home, I have to start cooking dinner, so I grab a quick snack for the kids, put on a cartoon, and get started. I always have a dinner plan ready, but I'm so tired and the husband isn't home and the kids want mommy to play... I never ever feel like cooking. As soon as my husband gets home, he takes a shower (because he works outside he has to take a shower... he's stinky and dirty). So, I'm left having to deal with the children and the cooking for a good hour before he's able to help. When he is finally available, he is as exhausted as I am, usually more. ANYWAYS. What I'm asking is... what can I do to make this less hectic? I already have dinner planned. I plan quick and easy meals. But I absolutely hate cooking when I get home. I would LOVE to be able to sit down for about 10-20 minutes and just relax... no kids, no cooking, nothing... just me and a moment of relaxation. Did I mention that I'm a high school teacher? So, maybe that explains why I'm so exhausted... Plus the two year old twins... What can I do? My husband hates boxed meals, but he doesn't complain when I make them because he knows how tired I am when I get home. Sometimes he will cook, but by the time he gets home and dinners ready, the twins are ill because its late... Is there any way that I can cook over the weekend and freeze it? I have a crock pot (slow cooker), but I don't feel comfortable leaving it on all day. I don't mind leaving it on over night, but I don't want to leave it completely unattended. We can't afford to go out to eat every night (but we have been doing that quite a bit here lately). I feel like a bad wife and mother because I'm not like my grandmother who can do everything and never complains. She would wake up super early and get everyone's clothes pressed and ready, she would fix breakfast and lunch, then she would go to work all day, come home, cook, clean, make sure everyone else was taken care of, and then she would finally go to bed. I know that I've rambled on about things that may or may not be pertinent to my original question, but I wanted to make sure I have enough back story so that I wouldn't get any answers stating something that was already going on. So, to get back to the original question... How can I fix dinner super easy and super fast?... almost like not doing anything at all. One more thing... I don't mind cooking. As a matter of fact, I enjoy cooking new things, but NOT when I get home every evening from a LONG day at work.