Could masturbation has side effects on health or fertility of male?

No. It's good for you, keeping you able to focus on other things and preparing you for being a husband / father. Frequent ejaculations lower sperm count simply because more fluid is available to dilute them. It won't make you fat, stupid, short, hairy, infertile, blind, or an unfit husband / father. Anyone telling you otherwise is misinformed. Think about real love rather than internet trash.