Thank you for the replies. @High Treason: That's an interesting idea, I hadn't thought about that. I have sometimes wondered if she says she's not ready to have intercourse with me because she's concerned about seeming too "easy" (Although I will say that I've privately found it odd that she's comfortable enough with me to be naked under the covers and share all those other sexual interactions with me, yet she's worried about what I'll think of her if we do that. Or maybe she's worried about what she'll think of herself...?) But perhaps to her, the foreplay and the oral sex and the manual stimulation etc. are more like "play," whereas intercourse would be more along the lines of 'making love,' and would carry much more emotional weight?

@Trippin 2.0 - Thanks for the point you made about stress possibly being the reason behind her not getting lubricated when we have been intimate. I have sort of assumed that it was probably because of stress, or nervousness on her part, or possibly some kind of fear (?) having to do with being emotionally vulnerable (which, like High Treason pointed out, would eventually come into play if she and I were to have intercourse).

I do want to clarify one thing though - she's made it clear that the feeling she gets of being "overwhelmed" is an emotional reaction, rather than being overcome with any physical reaction from kissing me. She's said it feels like it's "too much," and she has to break away/pull away in response. That's why I'm so troubled by it... it's definitely like there's some kind of "block" there.