Re: Can only get girls attracted for a short while...
Sounds like you scared her off. You don't need to "ask her out". Actions speak louder than words.
She was probably having a lot of fun doing all that sexy stuff with you, but as soon as you get to the serious part, she freaked out.
Let me give you a personal example. My current gf of 10 months, we've never had the "going out" talk. It all happened naturally. We met at a party, spent some time together with no pressure and eventually realized we are in this for the long run.
In my opinion, you have the tools to keep them attracted. You're not boring. But don't get too serious too soon. Keep things light for couple weeks, even couple months. Show that you're attracted to her, rather than saying at first. This has a much bigger impact on them.
Good luck with your future endeavours.
It's not about who I was or who I'm going to become.
It's about who I am. Do it right here, right now.