Hey everybody, can anybody tell me if these symptoms mean anything bad?

I'm 14 and have been masterbating for about a year and a half. I am a virgin and had no real sexual contact with anyone; and my parents do not have any STI's
My symptoms are that I've noticed that bumps above my shaft (the space on the back of the head). They've multiplied over the past couple of months and it scares me. They don't hurt nor cause complications. It just really bothers me.

It just really bothers me that there is bumps and it haven't really appeared before I started masturbating.
Can please tell me if:
1) If its a complications
2) If its a STI (I don't know how)
3) Natural Accordance
4) Please tell me

Thanks for reading and I love you if u give me an explanation