Every time I leave I have to tell myself that, as much as I hate leaving, I'd get bored if I stayed. There's only so much to do and see and buy. You have to give the parks time to re-generate and re-stock so that when you come back there's something new and exciting. Worst case scenario is that you get bored of WDW and fall "out of love" with it.
Plus, for me, I think I have as much fun planning the trips as I do actually being there. And, I'm not exaggerating about that. I almost get a little depression when I leave for a trip because it means all of the planning is done. And, while I'm on trips, I start planning the next one. I LOVE the planning part. So, there is always that to look forward to. And, even if you don't go back for a little while, that entire time you could be researching and planning.
And, for the really tough days, I turn on youtube tracks of the park music in my office so at least I can feel like I'm there