Re: sudden break ups
Don't take them to the movies on a first or second date. There's no way to build attraction nor talk. Yeah, you can Kino, but it won't get very far most of the time.
Keep your first dates simple - coffee, drinks, etc. Wherever you can talk, you're good. Read up on some of the guides here for how to handle first dates and whatnot.
Also, from what you wrote, there's no way tell whether or not you showed any interest. Next time, make your posts a little more detailed
Always leave her better than you found her.