If the reality is as you have mentioned, you have reached the age of puberty by (Part No. 11; Page No. 151) turning fifteen. Your ejaculation of Maniy is also a sign of reaching puberty.
Reaching the age of puberty for males is marked by three features: ejaculation, the growth of the pubic hair, or reaching the age of fifteen. We advise you to marry, for the Prophet (peace be upon him) stated:
O young people! Whoever among you is able to marry, should marry, for marriage would help him lower his gaze and keep his virtuousness and whoever is not able to marry, is recommended to fast, for fasting would diminish his sexual power.
(Agreed upon by Al-Bukhari and Muslim).We also advise you to repent to Allah for having
masturbated. Allah describes the Mu'mins (believers) stating:
And those who guard their chastity (i.e. private parts, from illegal sexual acts)
Except from their wives or (the slaves) that their right hands possess, - for then, they are free from blame;
But whoever seeks beyond that, then those are the transgressors;
Masturbation has many harmful effects as stated by specialists. May Allah set right your affairs, make things easy for you, and guide you.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.