After being married so long, it is completely normal for your sex life to be terrible. It's also normal for you to miss the romantic love you shared at the bginning of your marriage, but that doesn't mean that you two are no longer in love. Love matures as people do, and like people, it often becomes less wild and more practical. But often women are disappointed by this stage of love because it doesn't seem romantic, and they fantasize that a new man will appear and give them that romantic love. However, this is not very likely. What IS likely is that if you leave your husband, your children's lives will be ruined and your relationship with them will suffer irreparable damage. N., your children are all at very vulnerable ages. They need the stability of their two parents continuing to live together (provided there's no violence) in order to continue growing and feeling safe, to become themselves.
Think of your marriage as a car. Sure, if you sell it, maybe you'll win a shiny new Lexus on a game show, but probably not. And although your old car isn't as shiny or fast as it used to be, it's big enough for all the kids and it has good car seats and seat belts. It keeps your kids safe, and that makes it worth more than any new car on the lot. Feel you can't live with a less-than-ideal car? Well, you could spend your kids' college funds on a speedy new car, or you could spend a lot less on a tune-up and a paint job. You're still together after 13 years, which means you have a really solid engine! Don't trash a good car because you miss the days it ran faster and looked newer...fix it up, good as new, and know that when it came time to decide your children's fates, you did what it took to make them safe and happy.
Okay, metaphor over...I'm just trying to tell you that the investment you could make in couples counseling would be the best investment you ever made. If hubby doesn't like the idea, use the car metaphor (*cars* they understand!)
In the meantime, make a list of all your husband's good points, including the things that made you love him in the first place. Keep thinking about that list and how much you really love him, and when you do get a chance to be alone with him, show him you know how lucky you are.
If there's any chance you can switch to days, do it. Encourage him to look for work closer to home, and let him know that it's because you want to spend more "us" time with your sexy husband! Beg him to go to counseling with you; let him know that he'll have a chance to talk about how *he'd* like things to be. Chances are he's missing the way things were, too.
For the sake of your sons and daughters, this is a rough patch you will both have to get past together. It can be done if you both love your kids enough to do the work. Find a couples counselor you both like, even if you have to meet with several.
One great tactic is to pawn the kids off on a relative for a weekend, rent a hotel room, and leave hubby a message to meet you there. When he gets to the room, meet him at the door in the sexiest outfit you have (you know what he likes), and tell him how badly you've been missing making love to him. Once he's sweaty and exhausted, tell him that you want his permission to make a counseling appt. for the two of you. Tell him it's really important to you and that you aren't saying that the marital problems are HIS fault or your fault, just that you aren't happy with the way you two seem to be growing apart. Assure him that lots of couples go through it, but that you think counseling could nip any serious problems in the bud. Tell him you need to do it for the kids, and he may agree out of his sense of fatherly duty. Remind him that you love him and you think he's a great father and husband, and you don't want to lose him.
If he won't go, GO BY YOURSELF. Either way, it may be helpful to make up a "schedule" of time when the two of you can be together. Good luck.