Hi Fiona, and welcome to the forum!
I can so much relate to you story. I too started experiencing weird symptoms at probably your age, 41, staring with shorter periods, less heavy, nervousness, anxiety. I am now 43 married with two girs 12 and 7. Since I have never had such anxiety before in my life, i was quite worried what could be wrong with me. At the time I was prescribed AD and told that probably work stress and much travel were the reasons. A year later and anxiety did not subside despite the fact that I left my job which was quite intense, and had more time for myself and to rest. Fast forward to the begining of this year when I begin to feel dizziness, weakness, nausea, anxious to go out by myself, and excessive night sweats. I visited my gynea who did blood tests on day 3 of cycle (previous tests were done on different dates of cycle and weren't conclusive). I was quite low on estrogen, and fairly normal on progesterone. FSH was high bordeline. The doctor said that I am probably beginning perimenopause and prescribed herbal . Three months into the herbal stuff I didn't have any improvement, in fact I think I even got worse. Nausea, anxiety and sweats every single day to the point where I could't do my normal house tasks at all.
I then went to a different private gyneo and repeated the tests. He said I am definitely premenopausal and that all my problems stem from low estrogen and the disbalance that was occuring. He prescribed Femoston 2/10 and I am on it for 4 months already. I want to say that I feel much better now, most problems disappeared with some low moods and some anxiety still lingering but I hope with time these will improve, too.
Whether the age of 43 is normal or not for menopause I don't know, and I don't want to worry about this. My husband has been very supportive and we have both accepted that this is the case with me and we will together make everything necessary so that I feel normal again. Everyone is different but it is not unusual to begin experiencing symptoms at such an early age.
Good luck with your tests, and keep us updated,
Milamam xxx