Congrats! I myself am working on the C25K! I always found that the first run of the week is always the hardest, cause it is asking you to step out of your comfort zone! Day 2 & 3 of that week were much better, because you knew you conquered day 1, so you KNOW YOU CAN DO IT!!!
Honestly, I find that the later weeks, where you are running 5 mins straight (as opposed to 30 secs walking/60 secs running etc.) is easier!
Keep up the great work!