Who do I talk to about hair loss?

Hey there, I’ve been having problems with hair loss off and on for the past 10 or so years..I’d say from around the time I graduated high school until now.. The thickness of my hair is literally about half the thickness of what it was then..I’ve done the usual damage to my hair, blow drying, flat ironing, color and highlights, but alot of that was done AFTER I started noticing my hair loss. Now all I can stand to do with it is put it up in a pony tail (which that I know causes breakage) but everything else looks horrible because it’s so thin. When the problem first started I went to my regular doctor, told her about it and was referred to an Endocrinologist to have my thyroid checked. That turned up nothing and was summed up as stress. A couple years ago, I was at my gynecologist who is also a total women care doctor (she does stuff to help women lose weight, hair loss, etc) and asked her about it. I had another blood test to check everything, and nothing abnormal came out there. So, I guess I’m to the point of not knowing who to talk to about this. Do I go to a dermatologist? I just found on yahoo answers something about aromatherapy/essential oils….Does anyone have any suggestions?