Well I wouldn't go into the philosophy of if it the purpose of life or not, that is up to you, but in my opinion is it is not. It can have a variance of importance in your life.
For instance you could say for the matter of argument that in the case you work a regular 40 hour work week then sleep would be a third of your life(if you sleep 8 hours a night) and work is a third of your life during the weekdays. The rest of the time is divided up with personal things. I know that sounds overly deterministic, but just as a point of view. You could also divide your personal time into even different things, e.g., interests. For instance I like to study, read, and keep up on current events.
I know from personal experience that you can't live on love alone. I'm sure right now alot of people are probably discovering that right now as the economy tanks. Economic conditions can put a strain on a relationship.
But that is all for arguments sake.