Set out for my third post graduation run. Thought I might aim for 4k! I am slow!!!! The quiet lane I usually rundown was more like the m25 for some bizarre reason. I diverted onto 'my 'field. My knee which has been achy for a week or so was so sore....and I gave up after 15mins and1.5k.
Feel wretched and like giving up
X
Don't give up. So you did a 15 minute run instead of the 30 minute run you were planning on, no big deal - that's 15 minutes more than if you'd stayed at home. Look after your knee, have a rest and give yourself some credit - you've gone from a non runner to a Cto5K graduate, and one shorter run doesn't change that. It's a blip. Good luck with the next one.
Firstly you did NOT FAIL, failure is when you get back onto the couch and stay there.
We all have bad runs, sometimes for no apparent reason as well, we just have to put them behind us and get back out with a positive frame of mind. Often though one of my best runs have followed a bad one, so take heart and postive pants on for the next run, good luck 
As the others have said, it's not a failure. Anyway, just because you can run 5k/30 mins doesn't mean you have to every time. Bad runs happen to everyone. Chin up and don't give up! Good luck.
Chris
Noooo.... Don't give up !
I've just went through the same feeling after graduating. I've only been out 4 times and i had to give up my second run after 15 minutes from tiredness then the next give up was a mental give up.
Then my run yesterday. It was awful it was so hard i was barely moving but suddenly it all came together and suddenly out of nowhere I went from slower than a plod to running like I used to. From feeling down to full of enthusiasm.
My point is. You can do it ! It seems to be a common thing after graduating from what I've read, we all seem to get hit with problems. I so know how you feel. I was ready for giving up too. Hang on in there. All you need is that great run, which will come, and you'll be back in business. Your still a runner even if you miss some runs and give up a few times. No1 can take that away from you now.
I had a bad run one morning a few weeks after graduation - until I was talking to someone in the office about it and realised what I'd just said. 'It was a bad run this morning, I only managed 1.5 miles'. Hang on! *Only*?? That's more than I could have dreamed of before I started this plan! OK, so it wasn't what I'd wanted to achieve, but it was still a pretty good achievement in itself!
Keep the perspective on how far you've come. Sometimes things all seem to mound up and get in the way - unexpected traffic on a quiet route, physical niggles, time pressures. But you've come this far, you can keep going!
W5R2 - AM Run - Fail.
W3 R1- route planning fail
Epic fail & lovely hubby. 
Epic fail. Well, moderate fail at least!!
