Masturbating 5 times a day,sedentary lifestyle,eating fast food,extreme mental stress,very frequent fevers,etc.in teenage and young age for several years will surely stunt growth or height or height,growth,etc. is purely a matter of genetics?

Stress: It sounds like a combination of environmental factors as well as genetic. It's rarely if ever a matter of one over the other. I would get a consult from your GP, as well as a psychiatric evaluation with psychotherapy to follow to help you through this.

Growth: Excessive masturbation & stress will not stunt growth. Marked nutritional deficiencies could impact growth in more extreme cases. The bigggest factor is genetics.