Don't be embarrassed Rachb! First of all, a change of water & different food & routine can bung lots of folk up. Drink more water in this sweaty weather to help things along and try to relax.
Camp site toilets are often busy and a bit uncomfortable, clinical, and not a bit like home, which doesn't help either. Try taking a magazine with you & just sit. Women will be too busy with their own lives to even notice a cubicle with the door locked for any length of time. They'll be in & out in a flash so just r e l a x & it'll happen. You'll come to no harm if it doesn't happen. Some people go for days before they perform! Enjoy yr camping & try not to worry.