I was where you are now several years ago. I'm so glad both your kids decided to give being clean a try and I sure hope they continue on the journey.
I remember that once I dropped the second one off at rehab (they were in treatment centers 1500 miles apart)it took me several days to start to feel some release of tension. I was numb...I was running on fear and panic for six months straight so I had to "defrost." I spent the time they were both in rehab very focused on my own recovery and that was the absolute best thing I could do for all of us.
I hope you can sleep well knowing they are both safe today