Is it possible to get hiv's/ and std from masturbating?

well im wondering because i masturbate(alot,and i knowit's not good) and like a week or two ago i did it,im 13 btw, and that day i got these red bumps near my testicles,like right on my leg on the upper right calf or thigh in that middle area near my genitles and they itched alot and still do, i also remember trimming that day, so i know it aint exactly all about the question but im just worried like crazy, :(