On-going lifelong problems, doctors seem clueless. Help, please!?

Hi. I'm 25, female. My ENTIRE life I have struggled with becoming tired easily, and having trouble getting out of bed regardless of how much sleep I have had. I am overweight now, but I was not as a child and that was when it first began. As early as kindergarten I could not run as well as, and got tired more easily than my classmates. It was always extremely miserable to get out of bed for school, and I could barely function until a couple of hours after waking. This problem goes away if I awake on my own, preferably after more than 12 hours of sleep. When I hit puberty, I had ridiculously heavy periods, which continued in a slightly lesser form until late teens, when they became very erratic and varied between heavy and light. At 18 I was put on birth control to regulate hormones, and have been off and on it for years. It helps a tad when I am on it, but the problems come right back and I am tired of being on them and the last kinds I have tried made my problems worse. I suffer from bouts of extreme fatigue , where some days I am so exhausted I could sleep 24 hourse straight, yet some days I get almost hyper and clean the house all day. I have delayed or non-existant periods, and continuous stomach bloating/diarrhea. I also get really, unrationally irritable at times, epsecially if I am fatigued or having a hot flash. I also have OCD and am on Lexapro for it, but my irritablity does not completely go away with it. I have hot spells constantly in the summer, the slightest bit of heat makes me miserable and exhausted, and I have been that way since birth. I also have a weird rash on both of my arms/shoulders that has been there for about 8 years. It is like tiny red spots, some raised and some flat, that looks almost like really red freckles. It gets worse in the summer, but never goes away and only occasionally itches mildly. It seems unrelated to my soaps, detergents, etc. I also seem to have possible dermititis- my hands are always red even with the mildest soaps, though MUCH better if I avoid antibacterial soaps with Triclosan and was about 80% more sensitive as a child. I also had severe constant allergies as a child which have lessened by about 70% since puberty. My doctors always say "well, you need to lose weight and go on birth control pills" but it doesn't work! I do not WANT to be on birth control, it doesn't work and I am trying to have a second baby. I agree that I need to lose weight, but I have had most of my problems since childhood, when I was thin. I feel that unless I drop 50 pounds and can prove some radically weird sign or symptom that my doctors will never listen to me! I don't think I have some strange, unheard of illness, but I just want them to stop telling me the same unhelpful things. Does anyone have any idea what my problem could be? Anyone had similar problems or any idea for diseases or issues I could research? Again, my main symptoms are: fatigue, irregular periods, irritability, bloating, diarrhea, rash, skin sensitivity.