I treated my boyfriend for costo with goldenseal/echinacea. I use the Paradise Herbs brand for its quality and potency. Despite the directions, we used 2 caps twice a day for 2 weeks. He restricted has upper body exercises including swimming to reduce additional trauma to the ribcage.
You may also want to increase your intake of magnesium which helps relieve muscle contractions of all sorts. The best form I have used is the magnesium bis-glycinate form. It doesn't tend to cause diarrhea as much.
The water is also very important as it is a natural pain reliever, believe it or not. And the salt ensures that your electrolytes are balanced in a way that will allow your nutrients, including the magnesium to pass efficiently into and out of the cells.