I used to be just like you demon, which is funny cause i'm 19 (which if i remember is a lil younger than you). Same exact situation, fairly attractive(as told by others), but very little to no social life and absolutly no luck with girls. I think the situation you described must have happened to me like at least a good 40 times. The worst part is after she flirts with you, your dying inside for her to aks you out, but it never happens.
Here's a few things you have to realize if you want to have any success with females:
- A girl will never ask you out, NEVER, or ask for your number, no matter how much she likes you or is attracted/interested in you. There are exceptions, but those are very very very rare.
-But contrary to all that it's the girl that makes the first move. Either by giving you eye contact (not just a brief stare), making an effort to talk/conversate with you, and in general doing thing to make u notice her.
-If it's rejection you fear then you realy shouldnt worry because most of the time if the girl is not interested then she'll probably jus make up some lie and ask you for YOUR number, n she'll just never call you. Or she'll make up some other lie about a boyfriend, you'll almost never get a humiliating response.
-This is cliche but your gonna miss 100% of the shot you dont take. The biggest pimps/don wauns/macs get rejected, the difference however is they dont let it effect them, they just move on to the next female. If you ask 10 different girls out, and 3 accept then your batting 300 which is better than 0.
and from there it's all really mechanics like weather or not you actually know how to ask a girl out, asking for the number etc, but really thats all stuff you pick up on from experience.