How can stop semen leakage?im 16 and its really bothering me.?

so im 16 and have been masturbating since 11/12 and lately have been realizing leakage from my if i have an . i don't know if its just the stuff thats supposed to come out the pre *** or whatever, or if its actually semen,. today i was in bed with my girlfriend and i was feelin her up and makin out and stuff liek that and she was touchin my through my boxers and i went to the bathroomm and there was a area of wetness on my bboxers. im almost positive this is semen becasue of my over masturbation. i need a way to stop this and willl just stopping masturbation all togerher make it go away eventually? but if not how else can i stop this semen leakage form happening?