For full context see this document, Exercise 7.
According to my textbook, the brackets have to be filled with:
The sentence in question is the one at the very bottom.
I'd interprete it as follows:
"Because I didn't make it in time even though I went to great pains to be 30 minutes early and because I was warned by my husband that I must not say that I don't want to buy anything, it was a horrible day."
I feel a bit unsure about my interpretation because there are several clauses embedded into each other. Maybe you can confirm whether I did it right or not.