Excessive masturbation does not have any effect on the fertility, however it can risk you for problems with erections. In such a cause You must learn a healthy and proper techniques of masturbating. I would suggest you to get your semen analysis done from a nearby lab, it will give you information about the sperm quantity and quality status. Semen analysis is a better measure for fertility.
Next Steps
For understanding more about healthy way of masturbating and thing to follow for healthy sex, you may consult with me directly here on practo.