I know this is a super old post but thank you! Reading this makes me feel much better. I'm 42 my pr is 3:29, and am hoping to hit under 3:25, really hoping for 3:19. I have been following this same plan. I kept up with all the workouts, but they have. Progressively gotten so difficult I was feeling awful about my training. I am on the same workout that you were on the 2 miles easy, 12 miles or 100' @MP, 2 miles easy.. I couldn't do it, not even close. And mentally just even thinking attempting it made me exhausted. Hope your training that season ended well. I'd love to know what you ended up doing. I think I'm going to finish out my last 6 weeks with one of my older plans and just hope the rest of my training ends up ok. Thanks again for this post!