Headache or Plot Device?

Finished my Frenchman. Yes, it was fast but I'm realising that writing the first draft really quickly is kind of my process. I have to get it down ASAP because if I don't, I lose interest and never finish it. And since finishing is a weak point of mine, it's something I really have to work at and be disciplined about. Anyway, I'm already thinking that I'm going to have to change the middle of it. Why? Well, some explanation is required.

My hero, in the beginning, has a migraine that affects his vision (yes, apparently this is rather girly but hey, I can change it if I need to). Cue practical, efficient heroine who takes charge of him while he's extremely helpless. This ties nicely into his conflict of hating to be helpless, while at the same time, showcasing the heroine's trustworthy nature. Okay, this may have a whiff of the plot device about it but I'm keeping it for the beginning for the meantime (external conflict brings them together right?). However the whiff does get a tad stronger later on because he has another one - this one is different because he willingly places himself in the heroine's care for the first time, thereby demonstrating his growing trust in her and also having this trust repaid. But, I've already used this situation in the beginning so is using it again overkill? I didn't want him to have one migraine and then it never be an issue again (definitely a plot device!) and yet I didn't want to keep going back over the same ground. My gut feeling, though, is that yes, it's overkill. Not to mention the fact that it makes the whiff of plot device rather more stench-like.

The problem is that MH (and a lot of the other M&B lines) are character driven. I never really got a good idea about what this means until recently but now I do, I can see why my migraine thing may be just a plot device. Character driven means the character drives the story through the decisions and actions that they take. They don't stand there and have things happen to them. Hence my problem with a migraine. A migraine happens to someone, someone doesn't happen to a migraine. So really, if I want to showcase my hero's developing trust in the heroine, what should be happening is that a decision he makes places him in a situation where he has to trust the heroine rather than have the situation happen to him. But this is the difficult part for me - thinking of the situation! Because as a billionaire who hates losing control, why would he make a decision that places him in a situation where he has none? The answer probably will lie with the heroine and the chain of action and reaction that happens in the book. Somewhere along the line, she'll do something and his reaction will be to place his trust in her. In fact, I have an idea right now as I'm typing this....

What do you guys reckon? Is a headache just a headache or is it plot device? ;-)