How to get past awkward first encounters?

So I am a 22 yo guy in college with no (literally none) dating experience. From an outside view, you wouldn't expect this. I do well in social situations, I have a good social life and make friends easily, and must be decent looking because girls approach me from time to time. Its just that my awkwardness and lack of flirting ability prevents me from getting dates. But I am not awkward 99% of the time and I have confidence.

Here is a scenario. I get approached or meet a girl and chat a bit and its obvious she is flirting with me and likes me, but I freeze up and stumble over words so badly its frankly embarrassing. And any hope I have of landing a date goes out the window. I have had friends comment on this by pretty much feeling embarrassed for me and saying they had no idea I was that bad.

None of this makes sense though, because if I meet someone that isn't interested in me, I have the social ability like a salesman selling freezers to Eskimos. I have girl friends so it isn't that I don't know how to see girls as people. At parties I can be chatting with a girl but as soon as it has the hint of going somewhere or that she might like me, my social skills decide to disappear and it looks like a cringe video.

Other stuff I have tried. Online dating – don't get matches at all. Texting ability – dryer than the Sahara. Gradual escalation from a friendship to create a natural relationship? Yep, you guessed it, no social skills as soon as that happens, even If I have known the girl for years and have been good friends.

Any help would be nice.