I am right there with you as well. I could have written your post too.    I completed the C25K in March, but then soccer season started and I was off my schedule until the beginning of June. Off schedule means that instead of 3x a week, I was getting only 2x at most.   Now I am trying to get back on track but it seems like all I can do is run one mile and then walk because my lungs are bursting or I have yet another stitch in my side.   I am blaming the warmer weather....

....but in the meantime, I am trying to hydrate better 2 hours before a run, eat smarter meals before my runs, and trying to remember the breathing techniques I used when I was just getting started.  Due to the increase of side stitches, I cannot eat or drink less than 2 hours before a run.  And it is frustrating because I am impatient.  I will also be interested in what advice is given here. 

You might want to keep a running log for a couple of weeks to see if the quality of your runs correlates with other factors in your life (diet, sleep, stress, other forms of exercise, etc.) and see if there are any patterns that show up. Sometimes those patterns don't become obvious until they are written down.

I am guessing that you are relatively new to running, and that you never competed in races or engaged in a serious training program. If that is the case, you are asking your body to do an activity that is completely alien. It is going to take a lot of time and dedication. You need to be patient. Even elite runners have their off days. It is all relative.

I don't know what kind of surfaces you are running on, but if it is mostly street running or hard surfaces, the pounding will make you feel more fatigued than if you were running on a dirt trail or grass surface.

Another factor is your running form. There are a lot of videos on the internet about good running form that you can watch for free. Basically, you need to keep your shoulders back, hips forward, lift your knees high (but no too high) and keep you arms low but moving straight forward. It is good to focus on proper running form until it becomes habit. You will avoid injuries and run more efficiently with proper form. I have been running since I was 9 years old, and I still have to remember to focus on my form, especially when I feel fatigued.

The main thing about running is to enjoy and to remain dedicated to achieving your goals.

I feel ya!!  I had a CRAPPY 5k run today   This is my 4th 5k, and I did the Phila Broad Street 10-miler last month.  Today, I couldn't get to the mile marker before I had to walk and couldn't breath.    I was so upset, and more disappointed.  Does anyone think it could be that I'm normally an "evening" runner, and have been running on the treadmill to try to up my pace? 

I'd be happy though if someone could at least tell me that all runners have a bad day here and there...? 

ME TOO!!!  I am such a night owl   I can get up and run.  I do it every run.  This past saturday I think I just started off too fast.  I'm still sort of learning "my own way" you know?  It's only my 4th 5k, but I did do the Broad Street run.  To be honest, I had a goal too of beating a friend of mine and I think that was karma kind of kicking me in the butt haha! 

I don't even go to the gym in the morning.  I just can't do it.  Getting up at 5:00 a.m...uuugghhh and you had to get up and be ON!! 

  Any words of wisdom you can give are gladly appreciated!!!