Stranger passing through here, but my roommate and I recently started running, and she actually did couch to 5k. (I'm doing the Galloway method, which is not dissimilar.) A LOT of people hit a wall at week three; I think my roommate had to repeat week three, like, three times before she was able to move on to week four. So don't get discouraged. :) Take it easy, and have fun!