GO!!!!! It's good for your kids and it's good for you!!!!! I'm a SAHM so I jump at the chance to have some time away from my child. lol! I love my me time. My husband, who works, has a much harder time. Each time we leave our daughter for a date or overnight he has a hard time leaving her because he doesn't get to spend as much time with her as I do. Once he gets over the initial anxiety (which lasts for about 20 minutes after we leave her) he enjoys having some "us" time and sooooo glad he did it.
This is YOUR anxiety. Your kids won't even realize you're gone 20 minutes after you leave. The longer you wait to do it the harder it will be for them. This is good for both of you!! It's setting a great example for them. If they were adults with children and they were asking you for the same advice you're asking us, what would you say?? You're showing them that you are a person not just mommy. What a great lesson for them to learn, they can cope without mom!
A tip for when you go: Tell them for a few days prior what will be happening. When it's time for you to walk out the door don't belabor the process. Give hugs and kisses and tell them you love them and will see them soon and then LEAVE!!! The longer you stay when they're crying etc.. the longer it will go on and the worse it gets. They're fine. You're leaving them in good hands.
I can understand you're mixed feelings but like most things in parenthood you just have to do what's best and going is best for everyone. You will not fall to pieces once you leave them. You might be sad for a few minutes but once you start doing whatever you're going away to do you will not have your children at the forefront of your mind. *GASP* You will actually think about something else! You might miss your kids from time to time on your trip but it won't be so terrible that you'll be begging to go home. It's only a couple of days. When you get home you'll be surprised at how much more your appreciate your kids since you had some time away from them.
Enjoy!