Let me just say one thing. This helped me A LOT! Just seeing it from your perspective. This isn't at all how I function. I never would have seen it like this.
For me, people and situations are two separate things. If the person is no good, I could understand running (abusive relationships, etc.). However, a situation changes and feelings change. You could be in a rough patch one day, feeling like shit and be unsure about your partner. Then, the next day you get hit with a wave of awesome that wipes the slate clean.
The trick to this is letting go of yesterday. Yesterday is yesterday. It can't affect you anymore. It's over.
If I would have told my ex how many time I woke up and felt not-so-great about our relationship, it would have ended years sooner. But I wouldn't act on it, I would figure out why I felt like that. If it was something temporary, I would tell myself "This is just temporary. It'll pass." or I would take action to correct the issue.
Then, the next day I'd roll over and see her sleeping face all squished up in the pillow and love her more than ever.