Pourquoi le passé composé ici au lieu de l'imparfait?

Question

Pendant des années, je me suis plié en quatre pour arranger les choses entre nous...

t's describing something habitual that happened over a long period of tim. It's in the middle of a longer passage also in the imparfait setting the scene for a discrete action to come....

Thanks in advance for the insights I know you will provide.

Accepted Answer

Hi Laura, 
The passé composé is correct here, as it is something that lasted  a few years but is over now as explained in the following sentence -

... jusqu'au jour où je me suis rendue compte ... = ... until the day I finally realised

The perfect tense in this sentence conveys that the action, though prolonged, has a definite beginning and end, and is viewed as a completed whole.
Bonne Continuation !