A great story. I liked the part where Gil was trying to puzzle out what Sara had said.

Very good first effort, although it could do with another chapter, as there is no real resolution. And yes, you could use a beta to help you a little, although you're far better at grammar and typos than some (and who don't think they need help). I really liked how you got inside his head, and how his own self-thougths brought on his migraine. Now, if you just came up with what happens next...

Not bad for a first fic! Good idea you have here. There are definitely a few typos (nothing a spell checker wouldn't catch) and you switch verb tenses as well - are you telling the story in past or present tense? Other than that, good job, and keep writing!