Trouble with the second impressions is that, in my opinion at least, they really are the time to be yourself and provide the running-for-hills opportunity. It works out better that way in the long term, because if you're trying to make a particular sort of impression or _not_ scare'em off, it's only a matter of time until the reality comes out, and earth-shattering kabooms happen.

I refuse to believe that you are entirely undateable in general, but it may well be that, as a few people had already suggested, you're either starting out with the wrong demographic or spending your energy on other sorts of things.

In my experience the trick to finding people for whom one is not too odd is to do what one loves (in as far as "what one loves" can provide excuses for meeting other people who also love it), and working from the points of commonality. Hanging around strange people will lead to meeting people with higher appreciation for strangeness. (A number of the last N people I dated resulted from hanging around places where people indulge in odd hobbies. The rest involved meeting through friends from said odd hobbies. I do realize that with my particular odd hobbies, and I expect with yours, being female is an advantage as it gives one larger target demographic, but then, said people I dated had met _me_ that way, too, so it's not impossible.)