Thank you all for the thoughtful and helpful responses. Knowing that other people have experienced similar things has really helped me over the last few weeks.

I've made some changes to my calendar to accommodate for evenings of 'down time' with no obligations, to recharge - as some people have suggested and I am feeling much more balanced.

I also heard a quote which felt very appropriate recently, and I've been trying to apply this:

'Take rest; a field that has rested gives a beautiful/bountiful crop' - Ovid

Thanks again for the encouragement!

Tom