You can get both books from your local library - I suggest you borrow both and any other books that may be helpful.
If at all possible, practice in someone else's car on a private road (without breaking the law or causing annoyances) - you will be able to take your time without feeling pressured.
Or book another driving instructor for one lesson - tell him or her you want help with manoeuvring. Something may 'click'.
A lot of people have this same difficulty - especially women as the spatial awareness is different. It can't be helped, it's the way we are made.
Persevere, and good luck.