Perhaps after your bath, a warm pack on your abdomin would help you sleep. I use an old athletic sock filled with white rice, tied closed. Warm it in the microwave for a few minutes, then place it on the painful area for a soothing warmth.
Perhaps I'm Mg deficient or something -- I don't mind the Epsom Salt water mixture. I am definitely the minority.
Have a nice bath. As it cools, trickle more warm water in, so you can soak in the Epsom Salts for as long as possible.