My spirited child is only 3, so I haven't experienced the dynamics of 5-y-o, but these are things that help me:
1. Get enough sleep (why am I still up????)
2. Make sure she's eating well and sleeping enough.
3. Try to think about how the personality trait that's driving me crazy could benefit her in the future (i.e. persistence, unwillingness to give up/in, creativity, etc.) if guided in the right way.
4. Try to imagine how she's feeling in the moment.
5. If you're spiritual at all, prayer. This is my big one. If I can manage to specifically ask for help every morning, it nearly always makes a huge difference. I notice the days I forget!
6. Keep looking for support from people who approach parenting in the same way as you. That's one reason I love to come here. Share your frustration with like-minded people, so you can avoid having unwelcome suggestions wiggle their way into your mind, making you think, "this just might work and I'm so desperate, I'll try it!"
7. Always, always, always remind myself that LOVE is what works. Force will only get me half as far as love, and it will only stick for half as long. I've got to LOVE her to where I want her to be (in 15 years!), because I know I can't force her there!
Next week, I'll probably be the one here looking for support because my child's driving me crazy. But this week, I can see clearly enough to write all of that. Good luck!