The travel pillow is a great idea! My mom asks me if I need a donut cushion when she is around when I am dilating. I keep forgetting to look for one or something similar.
It really does take getting use to sitting with the dilators. I am almost a month post procedure and I can say it has gotten a little better for me. I still have days where it is worse sitting than others,though. I use the glass dilators 90% of the time which makes it much easier. I actually dislike standing up from sitting more. It feels like a vacuum sometimes if that makes any sense. I hold the dilator in when I get up because of this.