Relationship- need support

So a few times I wrote about a girl I was trying to have a relationship with. 

Today, she went down to support me during a presentation I gave in Parliament. Her train arrived late, she still met me and we spent a lovely day together. She was extremely supportive and encouraging today and really helped me make it through the event. 

We had a lovely, nice time together. I took her to the station, where I gave her the items I was handed during the presentation as a presenter. She liked it, but then she told me that she just wanted to remain close friends and that she didn't want to cause any misunderstanding or get my hopes up. 

I of course was upset, and she noticed it. She began apologising, saying she ruined my day and that she was sorry. She said she was really trying to be in a relationship with me, but never felt that way about anyone. She also said I'm the best person she ever met, and if she was interested, she'd be with me, but just wanted to stay friends. She repeated being sorry and ruining my day a few times, and I assured her that she didn't. 

Later on, she messaged me thanking me for what I wrote her (I told her not to be upset and that I still wanted to be close to her) and said she really wanted to remain close friends. We then continued planning Saturday- I asked her if she still wanted to attend and she said yes. We wanted to go ice-skating. 

Before this, we were planning things like walks in a forest and going to the Lake District. I'm afraid of losing all of that- and her- now. Even if she said she wanted to be close to me and began repeatedly saying how amazing my presentation was. 

I'm just really upset as I feel I'll never be in a relationship now. She looked physically and was mentally as if she was taken straight out of my dreams, I felt we had a connection, and I'm nervous I'm about to lose her completely despite her assurances.