Hi Over40
If your body has been without oestrogen for such a long time it can take a while to adjust, and in addition a certain amount of bleeding or spotting can be expected during the first 6 months of taking continuous combined HRT (ie oestrogen and progesterone every day). Have you been taking the hRT all the time throughout lockdown ie for 3 months?
The side effects you describe can be due to increased oestrogen, but if this is the case they usually subside after a while and the body acclimatises. Some women get ongoing side effects from taking progesterone all the time, like you describe, including the breast tenderness as well as the headaches.
You haven;t said how old you are. Also when you say you stopped having regular periods 4 years ago do you mean 4 years since last period or 4 years since they started becoming irregular? If the latter, and you haven't gone 12 months without a period, then you could still be peri-menopausal so the bleeding could be part of your natural cycle and as a result of ovulation,and this is more likely the younger you are, especially if below the average menopause age.
Many women who get side effects from progesterone continue to take it cyclically in order to minimise the prog exposure, which does mean though, having a predictable bleed each month. Maybe you could try this for a couple of cycles or so and see how you feel once you've had your bleed and you are on oestrogen only.
Also what dose of gel are you now taking? Increasing the gel until you feel better is a bit general really. I mean it won't necessarily bring you back to feeling totally normal ie your old self but should take you a good way down that path! Usually the advice is to increase the dose until your flushes and sweats at the minimum, have disappeared and then maybe tweak it to feel a bit better. Also each increase must be given time - a few weeks really - to settle before increasing again.
Hope this helps
Hurdity x