<human>: Condense the text into a few key points

So me and my girlfriend have been dating for 6 months. I thought everything was going great. She is by far the best girl I've ever dated. No question. 

Just into the new year she seemed like something was bothering her. I asked her if everything was ok and she kept saying everything was fine. Then one I day I confronted and asked if everything was ok between us and said she wasn't sure and agreed we should talk about it. The next day we met up to talk things through. She told me she thinks I'm in love with one of my friends.  

Quick back story on my friend: I met her almost 4 years ago in a time that I didn't want a relationship. As soon as we met we knew that we would be friends and nothing more. There is absolutely nothing between us. She is 23 and lives on the other side of the world now. I hadn't seen her in almost 2 years because of this. 

So anyway, I was was curious to know why she thought this. I still don't understand. She said something about the way I talked about her and how I acted when she messaged me. She also said that she knows nothing will happen as she thinks I've been friend zoned by her. I assured her that nothing has ever been there and she's just a friend etc but she doesn't believe me. 

There's a little complication. Before I met my girlfriend I booked a trip to the country where my friend is living. Not primarily to see her. It is first and foremost a ski trip and to see my sister who lives there. Also, I used to live there and have many friends to see. And I am on this trip right now.  

Lastly, I can see why she is a bit insecure about everything as before me her boyfriend of a few years cheated on her and I know that can take a toll. I had it happen as well. But I know I have always told the truth to her and I always try to make her happy and feel comfortable and everything. But now I don't know what to do!
<bot>: My girlfriend thinks I'm in love with my friend and I don't know what to do to prove that I'm not?