I am no authority on premenopause or lupus but I do have experience with both. First of all I would recommend you discuss your symptims with your primary care physician. I know that when I was peri-menopausal and menopausal I was not sure exactly what hot flashes were. I do know that inside I felt like a blast furnace and outside my body was cool and yes some times prespiring. It happened day and night and lasted for years. At night I was in and out of the covers a million times and during the day I was cold and hot at the same time. I found that I was especially bad if I injested alcohol (couldn't drink wine at all) or I would light up like the forth of July. Coffee and spices had the same effect. I did not choose to take hormone replacement therapy (although I tried it for a short time) and just rode it out. Now I am through those (and many more ) symptoms and llife is a little easier in that department. Today's doctor's still don't discuss the natural effects of menopause with women very often (even the female doc's). When you have a chronic illness such as lupus it becomes very easy to blame every symptom on it and just sometimes it could be something else.
I am/was a clinical therapist and one of my routine questions with women between the ages of about 38 and 54 was about their periods, symptoms, etc. especially if they presented with depression, anxiety, sleeplessness, mood swings and just not feeling right. Menopause is a natural process, uncomfortalbe at times "yes", but normal and every woman goes through it and it needen't be as scarey as those horror stories our mother's told (or didn't tell). To say for sure though I am glad it is over. There is life after menopause.
Hope my experience/ input has been helpful. Stay well and take care.