How do I proceed with the girl I am dating

I started dating the girl of my dreams 6 months ago. She is 2 years older than me. She has everything I am looking for and we get along very well. The catch is, she does not consider us in an exclusive relationship yet which means she has the freedom to date other guys as well. This bothers me so much because I am more sensitive than most guys and usually I would break this off if it was with another girl but I like this person so much I couldn't let her go. According to her, we are not exclusive until she feels its right and we have "the talk". She gets tons of admirers and she gets asked out regularly which made me worry and get insecure about 3 months ago and this was during her last semester in college which made her overwhelmed and asked for space. We stopped talking for about a month and we started talking again...When we started talking again, she said I should know better and I shouldn't be asking about other guys, this confused me since we are not exclusive. We started dating again and things got back on track for about 2 months till now because my insecurities are surfacing again. I feel at this point we should be exclusive and she should know if she wants to be with me or not, but I am not a girl and I dont understand how they think. According to her, we started dating from scratch after our hiatus. I should mention she is alot more experienced in dating and relationships. I only dated a few girls before her and none of them was an actual meaningful relationship. Also, our schedules don't match, I work during the day, and she works mostly during nights and has to prepare for medical board exam soon. Also, I work in the same city but I live about an hour away, but I am moving closer to her next week. We recently went on a trip and it went really well, except one little thing bothered me. She was texting alot when we were together, especially the one friend of hers who is supposed to be "just a friend and nothing to worry about" but I am sure that he likes her. I know that she noticed that I was bothered by this and the last 2 days have been a bit distant between us. This made me insecure all over again. I don't know how much longer to hold on in this current situation. I want a relationship, but I'm not sure if I bring up exclusivity she might feel pressured and put her guards up. I feel that this should come from the girl, but she has not brought up this topic yet. about 2 weeks ago she told me that "one day I would make a girl very happy, not just as a girlfriend but beyond that, as a happy wife" and that "they don't make them like me anymore". which makes me feel that she is interested in being exclusive but there is something holding her back. Is it my insecurity? should I just keep the course and suck it up until she brings up the topic? could she be dating someone else and keeping me on the side? I should mention, we have not had much of a physical relationship...she says she's "not ready" She had multiple sexual partners before me but according to her she is celibate and it doesn't bother her that we have not slept together yet. I don't know if I can believe that? I only had sex once and she knows it, she said that doesn't bother her and she actually likes that fact. Could this mean that she's simply taking a different approach because she knows I can wait for sex? i just don't know what to do...any feed back is appreciated. thank you.

Susie--I have been friendzoned before but this feels different? I feel like the timing hasnt been right yet...

JUST COME RIGHT OUT AND ASK HER WHAT'S HOLDING HER BACK. IF SHE KEEPS GIVING YOU THE RUN AROUND THAN THERE IS EITHER SOMEONE ELSE OR SHE IS JUST NOT INTERESTED. AND YOU WOULD JUST HAVE TO WALK AWAY. YOU ARE SHOWING THIS GIRL YOU WANT HER AND NO ONE ELSE. IF SHE MAKES THE STATEMENT THAT YOU WOULD MAKE SOMEONE ELSE HAPPY THEN THAT MEANS YOU ARE PROBABLY GOOD FOR SOMEONE ELSE JUST NOT HER.