Buy the truck you can pay for with cash that is set aside for vehicles, not from other projects.

Life is full of compromises.
You have to realize, and your wife has to realize, when you are compromising with each other, and when you are just compromising with reality.

The goal of POJA is to not compromise with each other, not to compromise your dreams, but to work together towards realistic things you can do right now, to serve those dreams, each other, and your marriage.