I can relate. I was 24 before I had a serious or for that matter any real relationship (and I'm still in it). It was long distance for the first couple years as well.
It seemed like the harder I tried the worse things got. So I had kind of given up, and then it happened (as in I found someone). I wasn't really looking for a relationship at the time though. So somehow I think there's some truth to not trying to force it, but just keep your options open. So that would be my only advice (if it is even useful advice) is to not try to actively seek partner/spousal unit, but just try to meet people.
I've wondered before if actively seeking a partner or trying too hard has actually scared away possible perfect matches (I've seen it happen with my friends, or at least from my point of view that's how it looked).
I agree with IamJen, it only has to happen once.