I agree with what everyone has mentioned and I think I need that book that was recommended.
Warning-I am heavily medicated with migraine meds, so this may not make much sense. 
I had a lot of medical issues to overcome ( still do), so when I seriously took up running I began by following some beginner running tips on Runners World. It was a great starting place for me. I run every evening and now can run twice as far as I previously could and in less time!
My breathing is no longer laboured, which I take as a good sign, but also as a sign I need to crank things up a bit.
Various observations-my son, a cross country runner (ignoring his age and young lungs) is a naturally "gifted" runner. He never struggled like some of his teammates did. When I run with DH, he struggles more than me. Some people are just not runners.
One things that helps me a lot is to take 1 minute fast walking /water breaks when I need them. A minute is not long, but it helps me run better when I do take those 1 minute fast walks.
I currently could do a 5k race without a problem (yay me)-that was my first goal. Now I just keep working up.
Oh, some days are just bad days, I do not know why. The other day I could not get through what I normally do. I have no idea why. So I listened to my body and walked a vast majority of it and cut it short.
Long story, work your way up, listen to your body, take fast walking breaks as needed (they do help), run as many days as you can. Come here for support-I do all the time. I have learned so much from the more experienced runners. Above all, enjoy running. It should be pleasurable. I find it a wonderful stress reliever.
Jennifer
“Live as if you were to die tomorrow. Learn as if you were to live forever.”
-Mahatma Gandhi
"We are what we repeatedly do. Excellence, therefore, is not an act but a habit."
-Aristotle