I kept posting and slowly I got better. I rewrote, edited and even learned how to employ a metaphor. It wasn't long until my mind was made up: I was going to be a journalist.
上面句子是2023年江苏南通高三一模完形填空题里的一段话。
其中, It wasn’t long until my mind was made up既不像是强调句型也不是It wasn’t long before...句型,感觉有点懵。
请问怎样判断和解读这个句子。