Last night I posted this on a few advice subreddits and asked how I should talk to my girlfriend about being nicer in public (sorry, I know it's a bit long):

"I have been with my girlfriend for about four months now. For context, we originally had a relationship that consisted of casual sex. As in, we made awkward small talk before sex, had sex, and made awkward small talk after sex, and she would leave. She seemed quiet, mousey, and shy, even during sex. About a month and a half ago though, when we were finished, she kind of opened up and started talking to me and having a real conversation. I thought, yeah, she seems cool, and I asked her out on a date. She agreed and we've been on about seven dates since. We've moved pretty quickly as we feel as though we have gotten over many of the common relationship hurdles already.

 I took her out to dinner on our third date and noticed that she left for the bathroom right before the server came to take our drink and food orders. She just told me her order and then left for about five minutes. I thought it was odd, but dismissed it. I took her out bowling for another date and she disappeared right before the guy asked for her shoe size. Then we went out to dinner the last two dates and it was just like the first time. This last week, I took her out for another dinner date and dismissed myself before she was able to about the time when the server came to take out order and when I came back she seemed more on edge, tense, withdrawn, and a bit irritated. I dont know if this has any correlation, but when we got to the parking lot she vomited.

Last week, we went over to my friends apartment for dinner. There was about ten other people there and I noticed that she was again withdrawn and tense the entire time. She didn't really make an effort to talk to anybody, but my friends seemed to like her and include her. My girlfriend went to the bathroom about at least six times that night and when I pulled her aside and asked if everything was ok, she gave me super irritated and short answers.

It just seems odd to me. Every girl I have gone out with has been super outgoing and loud, but she is just so reserved. She doesn't liked to be touched much outside of the bedroom or when it's just me and her and often crosses her arms, bites or picks at her nails, digs her thumb nail into her wrist, plays with her hair, etc so I dont hold her hand and often flinches when I put a hand on her waist.

She seems very into me when it's just me and her and when we're with her friends, but becomes a different person when someone else joins in. I really like her and want to make this work, I just dont really like the person she is in public. How do I go about talking with her about this?"

Since people have posted saying that they think she might have anxiety or an eating disorder. I dont even know where to start with this. We've only been dating for a short period of time, but I still really care about her and really want to make this relationship work. Should I talk to her about it? Should I just leave her alone? I dont want to bring it up and be wrong about it. How do I help her?