My mantra when i started to feel a bit like you (I was also at least a week overdue with my first 2 pregnancies) was "I will get to the otherside with my baby in my arms". No matter how scared i got I kept visualising already being on the 'other side' of the birth... tucked up in bed with my baby. During my third labour I found it incredibly helpful to stare at photos of my first 2 children when they were newborns.... I did this when I was in labour too... whenever I felt demoralised (my labours were slow). I know this is your first time but maybe gather up some beautiful photos of babies and look at them alot.... this might help to stimulate your natural oxytocin and help you manage things better both physically and psychologically.