Claire Weekes is wonderful - both her books and her audio downloads, Youtube clips etc.
Mindfulness would help you too, and is something you can practise wherever you are.
I have Crohn's and IBS, which can be problematic. Many members of a support forum I am on suggest carrying with you a small emergency kit - spare knickers, wet wipes etc - to help with confidence. Also, maybe wearing a Tena Lady towel or similar, just in case of accidents.
Like all anxiety and phobias, ultimately it's a case of working through your fears, by gradual exposure, so you realise that the thing that scares you won't happen.xxx