So my suspicion is that you're not being irrational, you're simply responding to evidence you're not comfortable calling as such.
I strongly advise against taking this advice in this particular instance. It constitutes some insight ("beware denial") and was a lesson that OrphanWilde needed at the time. However the overwhelmingly strong indication of Kenoubi's words (and also the correlated symptom "best two weeks of my life") is that Kenoubi is experiencing the oh so common effects of social anxiety and nerves that often comes when relatively little experience with dating. He doesn't need to be taking irrational fears more seriously.
I didn't offer any particular advice there, only suggested his fears may be rational; but it's an important caveat that merely because a belief is rational doesn't make that belief correct, which I suppose I should have been more clear about.
It sounds to me like the real basis of his concern may be the fact that he's making unreciprocated requests. I have no in-depth knowledge of the situation, so I'm merely hazarding a guess here, but if he's the one arranging all the dates (or whatever), an alleviation of his fears would require her to take a more activ...
I started going out with a fantastic girl a couple of weeks ago. Everything is great, except that whenever I've sent her a text message or email requesting something and haven't received a response yet, I experience significant dysphoric anxiety, fearing that her response will be not just "no" but "no and I don't want to date you any more". This is due to brain chemistry or personal history, take your pick—either seems like a possible explanation to me. But there's certainly no evidence supporting the idea that this is likely to happen, nor is the anxiety helping me prevent it or helping me in any other way.
Does anyone have evidence-based advice, or pointers to same, on dealing with this kind of issue? It is the only splotch on what have otherwise been the best two weeks of my life.