Socially retarded, somewhat confident and low self esteem.

Like the title suggests i'm all 3 of the above. I'm somewhat confident when it comes to men. I can ask anybody for pretty much anything i want. However when it comes to girls then i dunno what happens. I've been clubbing quite a few times and i've noticed that i ALWAYS get at least two girls standing next to me. I usually don't know what to do or say. I'm literally nor afraid of any guy. I could go up to the biggest beefiest brawniest guy and aski him anything while maintaining intense eye contact and not even flinch but with girls, virtually all stare at me like i'm some creep.
For example a few weeks ago i was in a club just dancing on my own in the middle of the floor when 3 girls come near me. I carried on then had the guts to ask one of them "Hey what's your name" She turned around and juts gave me this look that seemed to say "what the **** do you think you're doing" she then ran off with her mates and i just wanted to cry.
I usually notice girls just checking me out in the street and i just fele really awkward. I don't know why.
I should mention that i've NEVER had a good experience with women/girls. My sister rebukes and just abuses me all the time and i'm no longer speaking to her. My mum has no faith in me and she also doesn't think i'm capable of much and also abused me by not letting me go out with my mates when i was younger.
I'm definetly not gay coz i watch a lot of porn and get horny and i'd like a girl i can just SMASH HARD ALL THE TIME.
I don't get why people dont like me. I'm a bit of a social retard and i'm not usually clued up well so maybe people assume i'm a snob or just uninterested. I'm nice but not too nice. If someone makes the effort to talk then i reciprocate very well. I also dont like myself as i'm very skinny and have narrow shoulders and not manly enough. I can't drink a pint without throwing up or eat a meal in quickly like everyone else. One of my friends was saying that i'm a girl and laughed when i told him i've never had a g/f I cant play football or any sport without humiliating myself and i'm interested in stuff nobody my age is.

TL : DR
I'm somewhat confident but have ULTRA low/NON EXISTENT self esteem (dont ask how that's possible)
I can talk to guys but have NO idea how to engage with girls my age (19) I'd like a girlfriend as everyone has had one and they're all just ****ing each other all the time while i'm stuck with youjizz.com I fele like i don't deserve a girl/woman and that no girl could ever love me. One of mymale friends said that i'm "quite handsome" and says that he sees girls checking me out all the time but i never seem to see it myself.
HELP???

I can relate to some of the things your saying, Im the better looking one out of my friendship group, but yet the one with no gf...I have plenty of female friends, but no love interest. Maybe they think you're gay, my problem atm..