Hi Sam
Welcome! I'm new to the forum too so can relate to the need to ask lots of questions. You may well be sensitive to changes in oestrogen levels - I felt different after just 1 day of taking 1mg of estradiol cream - and it will certainly make you feel more “ra ra ey†as you put it! I also found that the estradiol made my womb feel more swollen and enlarged (this turned out to be adenomyosis in my case) but even without any medical conditions the HRT will wake up the oestrogen receptors all over your body including in your womb.
You need progesterone to balance the oestrogen unless you have had a hysterectomy or are completely menopausal. I eventually had the coil fitted 6 Months after starting HRT, as my oestrogen levels kept spiking and even though I was taking utrogestan (natural progesterone) my doctor was concerned that this was not enough to balance the oestrogen. I don't whether you have had the coil previously, although painful to insert i'm glad I had it done!
Hope this helps. I have a colleague who has early menopause at 42 and was prescribed HRT, she's been on it 10 years now and hasn't looked back! Mx