Totally confused by you

Met a girl last summer in a city that I live in overseas (her hometown), and we had about 2 months of casual but fun dating before she moved back to the US to finish graduate school. There were no commitments made when she left, but we kept in touch with the occasional email.

I recently returned to the US for a visit, and before I did, very thoughtfully put together a care package for her of things from her home country. We saw more of each other than I expected we would when I was in the US. Our time together was very intimate- conversation, PDA, sex, romance, dates, and several sleepovers. We basically were glued to each other for a couple of weekends.

I think by most anyone's judgment it had all the appearance of the early and euphoric stages of falling in love. I know it felt like that to me. And I told her in various ways that I liked her quite a bit. She said similar things to me, but I expressed myself more strongly.

I had to come back to her country and my job. We had a bittersweet goodbye at the airport.

Lost my job upon my return. I have another job possibility in the US. She's expressed an interest in staying in the US after finishing school. I wrote to her about my job situation, and asked her what she thought. I asked her if I came back would she want to see me again and maybe give a relationship a try. It didn't seem like a very controversial question to me, but it was. She called to discuss, and basically told me to back off. Said she's very complicated, is dealing with an issue, doesn't want to hurt me, needs time, wants to stay single, and that our time together was 'sweet' and that's about it.

It was pretty disappointing. I can't stop thinking about this person, and I want her. I have no idea how to navigate this, though. What did I misunderstand, and how might she come around?