If you are not married, then the relationship is a relationship of convenience, maintained because both parties deem themselves happier than they would be outside that relationship.
Accordingly, if the relationship isn't making you happier than you would be otherwise, end it. It might not be a simple calculation, but you are a fool if you don't make it.
This sort of thinking is the reason why I don't have a dog. I know that dogs can provide a type of companionship and can be entertaining, but there is a cost in time, money, attention, and inevitably, heartache. No dog for me.
