Crisis in confidence...

Am going through a major crisis in my confidence. After the 16 miles on Sunday I am trying to be positive, but I feel crap.How am I ever going to do this ? I am out with my Personal Trainer lady tomorrow and I hope to God she has some magic confidence beans to give me... some way to make me believe in myself again. I just feel like the little fat girl who was useless at Games again at the moment... Need to pull myself together.