Hello. I'm A 21 Year Old Female And I've Been

Hello. I'm a 21 year old female and I've been having problems with my stomach and discharge. During my menstrual cycle I experience very painful and heavy periods but aside from that I also experience spotting half way through. I almost constantly have very bad stomach cramps, sometimes after eating and other times it just happens. I have constipation, bloating and discharge which can range from thin and watery to brownish or blood. I'm really, really scared but I'm too worried to actually go to the doctor as I worry it could be something sinister. I've been looking up irritable bowels syndrome, polycistic ovarian syndrome, ovarian cysts etc and I don't know what to think. I also have a history of precocious puberty which I stopped treatment form when I was approximately 14/15 years old. Any advice will be greatly appreciated! Thank you