Yeah it can be incredibly frustrating to be dealing with this. I've dealt with it many times. At this point, it sounds like it's a pattern for you. The first question I ask, is, would you fuck yourself? Seriously, think of it from that girls point of view, would you find yourself attractive if you were in her shoes? And if not, then why? What do you need to work on? Seriously, it all starts with this shit, especially if it's a fucking pattern. You don't find yourself attractive, you wouldn't sleep with yourself, so why should they?
Secondly, as far as your technique goes, I sense a lot of hesitancy from you. I thread the line between a fucking cave man and a human in the modern 21st century... I'm aggressive as fuck while still making them feel safe. Like homeboy above me was saying, it can be a bit of a push and pull. Sometimes you'll fuck them quickly sometimes it can take a while, but either way, it's sort of a dance. You have to understand that while us men get turned on very quickly, for women, it can take a while, kind of like a nob on a light switch, where as we're more like an on and off switch. You have to ratchet it up. Women rarely are just ready to go, unless they're super horny or you're a celebrity. So knowing this, you work your way in her pussy by turning her on. It starts from the moment you see her. Being touchy, flirting, whispering in her ear, smelling her, a light pull on the hair, touching hands, holding hands (if you're crossing the street perfect moment), etc, don't wait till she's back at your place to begin turning her on. You'll find ways to incorporate these into the date as you get better. But you don't just go and grab her titties, you work your way into them. And if she gives you resistance, you back up a little, and then go back in. As long as she's still there and hasn't left, she wants some Dick. Always remember that. As long as she's still there, it's not a NO, but a no *right now*. So, just keep doing your thing and sooner or later it'll happen with one girl or another. But you have to be the leader and be the man.