Hia Jarl!
I'm still in peri, 8 months with no period. My symptoms really ramped up a year prior to me staring hrt 3 months ago.
I've heard the duration of troublesome symptoms(which is what I think your getting at)can range from 2 years up to 10 years, but once we are menopausal we will always be in menopause till we die, by definition of the meaning of the word.
The symptoms you mentioned like palpitations and anxiety are symptoms caused by lack of estrogen and are common for a lot of us.
Are you sure it was the hrt causing them? It's recommended to stick with any given hrt for at least 3 months before stopping to get a real feel of whether they suit you or not. As i say it's been 3 months for me and my symptoms have all but gone including palpitations since starting hrt.
We are all different, this we know, so it's going to be swings and roundabouts I suppose. Doesn't even follow in families does it.
I'm wishing us all a quick transition from bad symptoms to good ones, so we can get on with enjoying life to the max.