Need some advice about a girl

So I met this girl when starting my school year. I'm 21 and she's 22. She showed a great amount of interested in me and we ended up making out the first night we were out on a school function and talking for hours. We kept this going for a week, (sort of an initiation with the school), hanging out every night talking and kissing. This faded after the week ended, but we still talked a lot of walked to school every day together and kissed regurarly. Now I haven't had a girlfriend before, in fact i've only kissed one girl before her when I was a lot younger. She became a little worried about that actually and said "this might mean a lot more to you than me" and i found out that she has had a lot of boyfriends before me and a lot of experience. Anyway we kept this going, hitting a speed bump here and there, but she told me secrets about her that she doesn't tell her best friends. She tells me stories often that explain why she has problems committing to a relationship.

It's now 8 months later and not much has changed. The problem is that she is the most independant, for lack of a better word, girl I've ever heard of or met. She can go a week or two without hanging out with me and all she does when we are not hanging out is see her friends. We live like 10 minutes walking distance from eachother too, so that's not the problem. She can go a whole week without talking to me if I didn't initiate contact. And everytime when I have just about given up hope, she comes and drags me back in. She never wants to kiss me in front of others, unless she is tipsy. We can't hold hands in public. I treat her like a queen and she treats me like a dog it feels sometimes. She said once that she needs time, (it's been 7 months at this time since we met and we've been hanging out and kissing sporadically since then), I said "that's fine, I can wait. But is it worth it for me? Is there something waiting for me at the end?" and she said yes.

So my question is should i just be patient and wait? How long should I wait? She has had some horrible boyfriends that hurt her big time and I understand the fact that it's not easy for her. But this whole thing of her not needing to see me hurts me a little bit every day and makes me feel just worthless. 7 months of this behaviour, which causes me stress and anguish, is not fun. But I really care for this girl and I hope to be what she wants me to someday be, but I don't know how much longer I can take this.

In advance, thanks for any replies