Sexual frustration

Hello. First time poster.

I don't normally seek help for issues like this. But this is really frustrating me and I could use some non-generic advice from someone who feels in-tune with self-esteem issues.

Simply put, I'm having trouble with the ladies (I'm a 23 y/o heterosexual male). I have a decent history of sexual experience going back to high school but in recent months-maybe a year- I have been striking out constantly. I'm not particularly nervous around females and I believe they generally like my personality - at least the one's that are into nerdy types.

But I am not exuding a sexuality that attracts women my age. I am relatively short (maybe 5'7) and admittedly no Brad Pitt. But I also don't think I'm so unattractive that it should actively deter women who seem to otherwise find me interesting. I suppose a simple way to put it: I'm getting "friend zoned" and I don't know how to stop it.

For example, I am just now getting back from a coffee date with a girl I met through the internet (not online dating, just someone I had an interesting fb chat with from my school). I feel like we had a great conversation and she seemed to genuinely appreciate my listening skills and find me interesting in return. But by the end, I could tell I was friend zoned and seemed as though she simply didn't see me as a sexual figure.

I hate to talk about women this way, but I did feel as though she was in my league, aesthetically speaking (and I guess I don't feel bad saying that since she probably politely brushed me off based on my looks).

I feel as though it's something about my personality. I tend to be very caring and supportive which I think marks me as a non-sexual male figure. I know that dominant opinion would simply say "nice guys finish last" but I don't particularly want to believe that.

Does anyone have an opinion? It's really killing my self-esteem and leading me to want to give up and just collect cats.