Mature ladies: can we talk about perimenopause?

I will be 37 in March. I have been experiencing many symptoms of what I think might be perimenopause: change in menstrual cycle, insomnia (that is different from my usual insomnia), increased sweating and other not so pleasant things.

I know perimenopause is not something that can be diagnosed, so I was just wondering if ya’ll can tell me what your experience is/was like with perimenopause. When did you begin to notice a change? How did you know it was perimenopause? What were your symptoms? Did you do anything to help your symptoms, if so what?

I know the idea of perimenopause is somewhat new, so if you went through it before it had a name, did you notice changes before menopause began?