Only second period, HEAVY flow?? HELPPPP!!!!!!!!!?

so im 14 and i just got my second period. my first seemed normal, even light. but yesterday i got my second period (i got my first last month) and it seemed kinda normal, even most of today it was okay. but around 6 and after it has been horrible!! Im wearing a pad and like 20 things of tissue paper over my pad, and i have to change it constantly!! It bled through my pants and it was sooo gross, and just about 10 minutes ago, i got the WORST flow ever!! I felt it coming out like pee. i immediatly ran to the bathroom and the blood just gushed out like pee and i couldnt stop it and it was uncontrollable and now im just scared it will happen overnight!! What do i do?? Why is my flow so heavy? is it normal? What do i do to lighten it?? HELP!