Please, take the paid vacation time and spend it with your two young girls. You don't have to go somewhere in order to have a nice, relaxing, recharging time. How much time have you really spent with your young daughters, doing stuff with them? Do they live with a nanny, who is the one who gets to experience everything with them? Don't you miss that? You can capture some of those same experiences if you actually spend some time with them.
I'm assuming the anniversary trip next year means you and your husband--sans children? If so, then I would make it a priority this year to spend as much time with your daughters as possible, making memories they--and you--will always cherish.
As others have said, there is no way I would ever let any of my hard-earned vacation days slip away. You worked for them. You should use and enjoy them.
For me, that means spending time with my husband and daughter. I decided to get married. I decided to have a child. Therefore, I decided to have a family. It's not all about ME and my life and my work and my wants. There are OTHER PEOPLE in my life that I have to think about. I made that conscious choice--to have a family. Therefore, taking time to spend with them is of upmost importance to me.
Everyone needs to take time and recharge. Being a hyper Type A person and on the go-go-go all the time and never taking any time off for either yourself to de-stress or to bond with your family isn't a good idea. If you don't find a way to balance your home life with your work life, you just might start finding yourself sick--heart attacks, strokes, adrenal fatigue, chronic fatigue, migraines, or whatever else your body will use that will either shake and wake you up, showing you that you need to reevaluate and relearn how to live so that you're managing your work-family-personal life in a better manner, OR maybe you just might find yourself one day being so sick, you're totally and unable to work. Then where would you be? Unable to do what you really love to do--work.
You need to find some sort of balance in your work--personal--family life so that doesn't happen.
I'm reminded of when I was younger and worked in a small investigations firm. I was the office manager/financial person and was very involved in running the office--I was the only person doing any of the admin work. It was stressful and demanding and I loved it! But every year, in December, I would get horribly, horribly sick and would miss at least an entire week of work. It was the worst time of the year to be gone, because that was when we billed out our biggest billing period and closed out the year's financials. This went on for 5 years. Every. Single. Year. I got this sick. And I was frantic and totally dedicated to my job and always fretting, always fretting.
One day, my father asked me why I was acting the way I was. He said, did I own the company? I looked at him and said, no. He said, if you were hit by a bus tomorrow, what would they do? I just looked at him. He said, they'd find somebody else to do your job. You don't own the company, and you are expendable/replaceable. There is absolutely NO REASON to be beating yourself up, killing yourself, for the job. You don't own it, if the company tanked--you wouldn't lose your shirt, you'd go and find another job. And if you were to die tomorrow--they'd find somebody else to take your place.
Put your job into the perspective it needs to be in. There are other things in life than working. You have two precious little ones at home who would like their mommy to spend more time with them.
I suggest you do so.