I am terrified for my kids to fly alone

I need to vent. My boys are going to be flying out to visit their Dad for the first time, during Thanksgiving break. We agreed that since it’s the first time, one of us would accompany them there and the other one, back home. For reference, they are going from Orlando to Dallas and their ages are 13 in January, 11 in December, and 8. Well, when Dad booked their tickets he did so as unaccompanied minors and I am terrified. My older boys did this a couple of times when they were younger and while I didn’t like it, I was ok. My issues now are that one, this isn’t what we agreed on and two, that the world we live in now, is just not what it was back then. I wish I could fly with them but I’m recovering from surgery and can’t travel. I know I need to make peace with this but I was just blindsided with this today. Does anyone have any positive experiences with their kids flying alone that they can share? They’re flying Southwest. Thank you!