<human>: Can you succinctly summarize the text in 1-3 sentences?

I'm graduating high-school end of next year, and then I'm planning on going solo to the UK to pursue my dream career.

My best friend, however, has other ideas. She's literally under the impression we'll be getting married and moving overseas together. We have a bit of a weird relationship --- we're dating (except we haven't acknowledged that we're dating), and she's happy to flirt with other girls as long as she knows she has "first dibs" on me.

I'm getting tired of it. Either we need to officially date or I need to stop being around her. I've tried just *not* having feelings for her for three years and it doesn't work, it's all or nothing at this point. And I'm not even sure she's somebody I'd want to spend the rest of my life with anyway; she's very full of herself and puts me down a lot when I achieve something she's incapable of, and she's just all round an extremely jealous person. I love her dearly and I'm closer to her than anyone in the world, but I'm just sick to death of being sidelined.

I mentioned to a friend that I was looking at internships in the UK, and she went, "oh, how are we gonna afford to live in that part of the UK though?" I don't know how to tell her that this dream life she's got in her head isn't happening.

And is it weird that I'm okay with leaving all my friends behind? The majority of them have turned out similar to said best friend, very arrogant and snobbish. I'll miss them a lot, but I just want to go to a new country and start fresh and independent.
<bot>: Pseudo-girlfriend thinks we'll be together forever --- I just want to go overseas and start a new life after high school.