ToeJam, YEEEEEYYYY!! : "and on Wednesday I'll endeavour to go in with it as it is... and sod what happens after". Keep that thought!!!!
And if you're feeling bad, that's OK, you're entitled to, and it matters!! It isn't always an easy ride going through what you're going through/to come out the other side. Let them know it matters, it is what it is. And you deserve support/help.
The book: Yes that sounds tough to pick up on feeling how you feel. Sounds a demanding thing even if you weren't feeling depressed, so good idea in giving yourself a break. Perhaps see it as something you'll try to pick up on in one/two (?) months. It's not something you aren't going to return to, just not right now.
But I know things are really hard for you, don't push yourself more than is comfortable, give yourself real credit for what you actually are achieving/managing, and don't fault yourself!!
Here for you......
Alison

P.S. Apologies for no response to your first message about the sections of the brain, really out of my depth there. Sorry!!