Never stop trying, take little steps towards your dream!
I am thankful to finish a 10km run without feeling nauseous. I have never imagined finishing a 10km race or even sign up for 2 runs within a year!
I felt I've made significant improvements from the beginning of this year (2016). There are little techniques and tricks that can help you get closer to the goals that you never thought attainable! Yes, just "little techniques", and that's taking a small step each time, setting small goals while taking note of your progress.
Usually I would set parameters for each run. Sometimes my objective is master better breathing or pacing. Other times; is to improve the timing. Comparing my performance against previous runs and setting attainable goals have helped to increase my confidence in running. Within 2 months, I pushed myself to run a 10km race from a 5km one.
I am sure, there are other ways to build up your stamina and strength but the key is to understand your health and how much your body can take!
P.S. Running is addictive. :/