Hi Henderson - sadly we women are educated about puberty but not about what happens with menopause. Do read up all the info on this site to get clued up.
Many of us would love to use oestrogen alone to help maintain our bodies better beyond menopause but it's often the progesterone that we have to use alongside (if you still have a womb/uterus) that can be the troublesome bit of HRT for some women.
There can be many reasons for feeling down and have low mood but the menopause is called ‘The Change' for good reasons - our bodies are reacting to the loss of that wonderful engine oil, oestrogen, and sadly the only way to replace this is HRT. Some women suffer less than others and if you want to try HRT(provided you don't have any health issues that would prevent this) then give it a go to see if it helps you. Some lifestyle changes can improve things, so try this first - try some Vit D supplements, eat a good balanced diet and up the exercise to see if this helps. DG x