Possible early menopause?

This is a little personal, but I'm hoping someone may have some insight that will help me. I was wondering if anyone has been through early menopause and would know what it's like. I'm asking because my periods, although I do have them monthly and pretty regularly, are out of control. I go through a tampon an hour and have HUGE blood clots. I even have to get up and change my tampon during the night because if I don't I will end up with a trail of blood that leads from my bed to my bathroom in the morning! I have recently been having trouble sleeping. It takes me forever to fall asleep, and then I wake up several times during the night. Sometimes I wake up sweating, sometimes I wake up freezing. I have never been like this before. I have been getting migraines and very sensitive to light. I have been to several doctors, and they all tell me there is nothing wrong, but I know my body, and this just isn't right. One doctor even told me if I lost a little weight and got closer to my "ideal" wieght that it would stop. I know that alot of this was probably a little TMI for some, but any (educated) info or advice you may have is greatly appreciated. Thanks in advance!