I think I can add an interesting perspective on this. My boyfriend has a friend that sounds a lot like this girl. She gets mad about whoever he dates and doesn't like them. She doesn't explain why but expects him to treat her like a princess. Now, I don't think she likes him like that, but it is more of a dependency. I know she doesn't want him sexually, but she does want someone at her beck and call. The problem is that it isn't fair on me, the girlfriend. Girls like this in general have a good guy friend and don't want to lose the attention that this friend will give them. I have had this in a previous relationship as well. It isn't your fault, some girls like someone who will do anything for them, and it sounds like you are falling into that catergory. The bottom line is that you can NOT run your life around this girl. If she is really your friend, she will either pick you up or let you have your own life. Not letting you date anyone else without getting jealous? That is not cool and you need let her know, in a nice way, that this friendship doesn't revolve around her whims, plain and simple. You can wait, but not to long. You are not living your life for this girl.
