“Intense period?”

I turned 16 in the summer and I just got my first period on Oct 3. I was on my period for 24 (ended on the 27th) days and it was extremely heavy (I bled through a tampon in under an hour), and I had externally painful cramps to the point where I couldn’t walk or really even move. I also was very nauseous and threw up a few times. Then I got my period again on Oct 30. I am still on my period with the same symptoms as last time but slightly more severe and I am also fainting a lot (at least once a day). I have increased my iron by a lot and I am making sure to eat plenty of food and drink water. I am also taking Tylenol for the pain but it doesn’t help that much. There is also no history of any menstrual disorders in my family, and my younger sister who got her period before me when she was 13 hasn’t experienced any abnormalities. I don’t know if this is something you can answer for me with just the information I’ve given, but if you could give me some idea as to what is going on it would be greatly appreciated! My mom just says it will work itself out but I’m in a lot of pain.