Yourself as "part of a couple" ?

[teeny]

Hi, I've been lurking a bit, and really like all the good advice I've found on these forums. Here is my problem, I'll try my best to articulate it..

I just spent a few days with a guy that i really like- he lives across the country and came here to visit me and some of his friends- I met him on vacation. We got along so well when I first met- I wasn't under any pressure or stress, and wasn't looking for anything, so I was just being goofy and myself. However, once I like a guy, or know they like me, I change. I felt a little awkward when he visited, even though he had a great time, it really bummed me out. I become so much more aware of what I'm saying and can not relax enough to be myself. I worry about what to say and basically am really quiet. I don't know what couples talk about, and can't imagine having a boy that i'm sexually attracted to as my "best friend" even though its what I'd want. I feel like the sexual part gets in the way, that I don't really trust why they even like me, and I just put myself under way too much pressure. I'm never confident that a guy likes me for me because I start to feel like this other person. I just got out of a 3 year relationship with someone that I was very close with, but for some reason, it never really "clicked" in place. I would still feel insecure that I didn't have enough to say or entertain him with for more than a day or so in a row, and would avoid having to spend too much alone time with him because I didn't want to bore him. I know i'm somewhat introverted, and I'm okay with that, but I wish I could work a little more on saying what I'm thinking and being a little more outgoing and trusting. I think I have a lot of insecurities coming out of that relationship because half the time my ex-bf made me feel like I was perfect and put me on a pedestal, and the other half the time, he would say things like, maybe we don't have much in common. I tend to like guys that have a quick wit and tell good stories- maybe because I wish I was more like that?
It's weird, because before this 3 year relationship (i'm 23 btw), I had a few relationships for a month or so and I didn't worry about this kind of stuff. I was ecstatic to spend a bunch of time with them in a row. I had a really intense relationship in 7th grade (i know, longggg ago) where I would talk on the phone with this boy for 5 hours a day, every day, for months. What do seventh graders even have to say?? I think once that ended, it def. changed the way I interacted with the opposite sex, always limiting my crushes to guys I knew I couldnt have. But the few other relationships I had later in life still didn't have the problem that I am finding now. Maybe I just have confidence issues- or my last relationship really made me doubt who I was, but I'm completely okay outside of a relationship or when I am friends with a guy- it's just once I know that they like me, that I begin to have issues. Can someone offer some words of wisdom and advice? Its not that I am a boring person with nothing to say, I just feel sort of stunted when it comes to relationships- like I never really fully developed the part of me that is "part of a couple". Is that something I can learn?

[weary]

teeny,
while i can definitely understand where you are coming from having been there at one point in my life, your second-to-last sentence in your OP jumped out at me as RED FLAG: never really fully developed the part of me that is "part of a couple".
this is the problem. don't look to be defined by a relationship nor your role in one. you said yourself that you start to act differently once you start to like a guy/know he likes you. you've got to get to a point where you are comfortable enough with yourself to be yourself regardless of being enamored. once you are able to do that you will not only enjoy romantic/intimate relationships better, but feel more confident in them b/c you'll know that the person you've presented yourself to be is your true self and that's why they will have fallen for you - not some alter ego you have when you can't relax and feel the need to fill-in quiet spots with conversation. just think of it the way you are with your close friends. you are yourself, right? and they love you, right? so do you want to build a relationship with someone based on your true self and achieve the kind of closeness you have with your close friends, or build a 'surface relationship', like the ones you have with say, coworkers or other people that you present youself differently to?