Quit being so damn nice for one. If she doesn't enjoy having you around, it will be a lot easier to leave! Only half serious there.

I have it pretty good in that my wife understands how much having my own time and adventures outside of "us" means to me, and she fully supports that. As others have said, expectation management is key. Her expectations for our time together have been low from the start in knowing that I am gone for 2-4 week chunks of time throughout the year both for work and fun. That is a part of me, who I am, and who I will always be. She chose to accept that. Making sure she gets her opportunities to do what she wants and generally feels fulfilled goes a long way as well.

In your case, she obviously has a preferred way for you to spend your time other than doing what you would most like to be doing. What is that? Hanging with her? Honey-do-list? Working? What is she not getting that she wants? It is always a give and take game. Ideally you are both giving and taking about the same, but most of us wouldn't probably say there is some imbalance in our given relationships...true or not.