I'm 13 years (5 months) old now, and am at stage 4.5 on the calculator. I stated stage 4 when I was about 12 and a half. Is that abnormal? I first started to see signs of puberty when I was about 7 (pubic hair, armpit hair, random erections). I even got sucked into porn when I was 6 or 7. Whenever I did, I got an erection and pre-ejaculate always came out. Is that abnormal to start puberty that early? And have pre-ejaculate at 6?
To develop that early is called precocious puberty. Having noticeable signs of puberty before 9 in boys is considered precocious. Generally when someone has precocious puberty, it is advisable for a doctor to check them out as there are some illnesses which can trigger early development. Most often, however, no cause is found.
Because you started development from a shorter height, children with precocious puberty tend to be shorter than most.
Well I did get type 1 diabetes a few years back. Could the early puberty have caused this?
More likely the other way around. Having diabetes, even though it wasn't discovered yet, could cause precocious puberty. "Syndromes that involve glucose tolerance and insulin resistance, including diabetes and diabetes mellitus, also cause early-onset puberty in children." ["What causes early puberty in children"]. This is an example of why unusually early puberty is supposed to be checked out.