Found run 3 on week 5 totally fine. I even ran for probably 22-23 mins. So for some reason Week 6 run 1 and run 2 were so so tough. My legs felt heavy and I nearly got a stitch, one of the things that I really suffered from before starting the program. When I got to week 6 run 3 I was really anxious and sure enough within minutes of starting the run it didn't feel good. I quit after like 13 mins. It didn't help that my bf broke up with me the day before. I ended up stopping in a park and having a little cry but that's another story.
So then I didn't know what to do. Go back to beginning of week 6 or just repeat that single run. I read somewhere that someone got through it by focusing on breathing right at the start so I that's what I did. The next day I repeated week 6 run 3. I slowed right down and really focused on my breathing and guess what? I did it!!! Comfortably enough to even up the pace for the last 60 seconds. So basically my advice to anyone with this problem is SLOW DOWN. I made sure my music was nice and loud cause I didn't like the sound of my slow plodding footsteps and really I feel confident about progressing on! I'll worry about going faster a different day. I comfortably kept running for 25mins and I'm super super proud of myself.