Does excessive masturbation affect my chances of having children in the future?

Age: No, not for a male. Age is a factor for women. She is born with all the eggs she will ever have. As they age, conception becomes more difficult.

No impact: Will not affect future fertility.

Masturbation: Nope. Not in any way. Masturbation is a common part of the human experience. Nearly every man you know or have met masturbates or has masturbated. This common sexual activity will not affect fertility.

No: I'm really sorry that somebody troubled you about this. One of the cults here in the US is peddling some phony science to frighten male teens. It's bunk. Sperm counts are lower if a man ejaculates more often because prolonged storage concentrates them. Only if you're so focused on private fantasy that you're not meeting women at all will it prevent you from becoming a father.