Former anorexic and perimenopause

I am going into my 40th year and been a "recovered" anorexic for 12+ years. While my cycles have never been regular, I'm beginning to wonder if I might be experiencing early onset menopoause. Over the past 7 or 8 months I have experienced odd things happening. It started with bouts of vertigo this summer that one ENT said was an ear infection (odd because I've never had an ear infection and my ears didn't hurt). New doctor told me it was my sinuses drying out, so I got a neti pot and that didn't make much difference. It eventually "went away" in early November. But one thing that stuck...the almost daily occurence of what I can tell is crash fatigue -- ya know, can't keep the eyes open, then I'd get heart palpitations and I'd freak out because I couldn't figure out what was going on. Then...an hour or so later, gone. I've taken to the "duck waddle" to the bathroom after strenuous activities like exercising or shoveling. Sometimes I'm not all that successful. There's also been several occasions when I've woken up in the middle of the night or the next morning, drenched in sweat despite wearing a t-shirt, shorts and using only a blanket with a house at 65-68 degrees. But the one thing that kills me...as a former journalist who could quote anyone from memory and knew exactly what was going on when...sigh...I am so forgetful anymore and focus at work is nearly impossible. So my question is...do you think this could be perimenopause? Do the symptoms ever go away?