okay, heres the deal as far as i can see it. . .
you should see a psychologist. . .no really, i do and i have plenty of friends and girls and whatnot, as far as im concerned everyone should. they are a great person to talk to even if it just allows you to "converse with yourself".
next, if a girl is less talkative or different around her friends, that is normal, welcome to women. if she is drastically different, even mean to you around others, she is not your friend. you should talk to her about it and if that doesnt resolve anything, move on.
speaking of moving on, you think too much about things. i spent a hell of a long time with a lot of people not liking me because they could tell i was just trying to fit in. ive since gave up that bs and just am who i am, and now ive just become the smartass mad scientist of the school. im neither all that attractive nor wealthy but i went out being myself and eventually i made friends just because they knew that they will always be talking to the same me.
lastly, your paradigm(sp?) on women is a bit skewed. for your sake i hope you find this one girl who is amazing and you marry her or whatever. but youre probably going to learn that thats not how it works. people date, people "date" (physical relationships), people just hang out, and people get married. most of the time you'll be part of at least a few of these different kinds of relationships, often multiple times. yes, people get hurt, yes people have to be attracted to eachother, and yes sometimes hearts get broken. but i can tell you from experience that even a fun, interesting relationship that only lasts 6 weeks easily outweighs the heartache that arises when it ends.
just go out and have some fun while you still have some time, and when it works out hit me up about it.
-Doug