Sometimes faking it until you make it works best...now before I get shot, let me explain more...
No, I'm not talking orgasms or things like that. I'm saying take time for yourself (I know that is few and far between with kids, but it helps). Take a bath or put on a sweet smelling lotion, purdy yourself up...just for your husband. He will notice, I promise! Try to drop the kids at a friend's house for a few hours or overnight and have a "date night" just the two of you! The more effort you put into the night, perhaps the more interested you will be in completing the night romantically!
You could schedule a movie at home with a "picnic" dinner on the floor, then a bath or shower together or something quite romantic like that that isn't going to be interrupted by little knocks on the door since the kiddos will be elsewhere! My husband and I have even bought a fun, sexy game that we pull out occassionally when our love life needs a pick-me-up (or there is always the classic strip-poker or checkers or whatever you have around the house!!!)! Even if the night doesn't end in the S-word, you will show your husband that you are making an effort and he will feel special and appreciated rather than taking it personally!
Also, I am very dry "down there", so sex is often VERY uncomfortable for me (except when I'm pregnant...yea!!!) so I always make sure to have LOTS of lubricants around...that might help you too! The best type is one without (I think it is) Glycol in it which tends to burn. The off-brand at Walmart doesn't have it in there and is great...though I'll often try others just for something new! Sometimes just going together and buying something sexy helps too!
Think of things that you did together when you were dating, before marriage and kids and tap into some of those ideas!!! But be honest with your husband about what is going on with you and your body.
The idea is effort though. I try to do something special for my husband at least once a month and he does the same for me, so it is not just one sided! And find another couple with kids that you can switch off with for the "date night" babysitting. It will be free and I can guarantee the other couple will be appreciative as well to have an excuse to go out! Hope some of these ideas help and good luck!
S., 26, married for almost 5 years and have a 1-year-old and another on the way!