Actually, there's nothing wrong with the word bibliotherapy. You can see what it means, and it's Greek all the way through.
It's even perfectly straightforward to pronounce.
The reason I object to the word bibliotherapy is that it gives credence to the idea that it's worth paying money to ask someone to suggest books to make you happy.
I expect someone will legislate on this, soon, and then we'll have degrees in bibliotherapy, and unqualified people will be banned from making our own suggestions. So I'm going better get in quick.
If you feel low, then these books might well make you feel better:
Anything by Jane Austen, Agatha Christie, or Dorothy L Sayers. PG Wodehouse's golf or Mr Mulliner stories. The Hitchhiker's Guide To The Galaxy by Douglas Adams. The Ogre Downstairs by Diana Wynne Jones.
Obviously, I could go on and on and on. But I won't.
After all, fleeting rays of sunshine are more cheering than the noon-day sun.
Word Not To Use Today: bibliotherapy. The Greek word biblion means book, and the other Greek word theraps means an attendant.
Now I think about it, you can probably get some excellent bibliotherapy from any bookshop or library near you.