Attachment and need support

So, in a week I will be going on an overnight retreat with hubby, and we'll be away from the kids (youngest is 11mo.). I am dreading it beyond belief, that is, being away from the kids. I know hubby and I need this and that I have been away from the two oldest overnight before (giving birth to the youngest), but I've never had it where both of us have been away from all three. That is where my anxiety comes in. I have to keep telling myself that everything will be okay, but my imagination goes through worst case over and over. No sitter seems perfect enough (my mother-in-law and sister-in-law will be at our house watching them - and yes, I do trust them as much as I can given that I also have trust issues with anyone beyond my husband and me). Have any of you experienced this?