Heyo lass. Checked out your full situation (thank you for the detail - sometimes it is good to use the question box twice) and I gotta say this guy sounds more like a zero than a hero to me. But not for the reason you might think.
A relationship is ideally an equal partnership. You are invested in making this one work, he, to be blunt, is not. From the other details you provided, he probably never will be in the way you want.
Now, before you boot him out of your life, it is time to sit down and have a long chat with yourself. Why did you get back with him? Why do you tolerate his lack of attention? Do you really think that is all you are worth? Most importantly, why is he failing to meet your needs?
I am not saying he is a bad or neglectful person, or even a bad lover. He is not. He is, however, not the person you need to be with right now. You need something he, for whatever reason, simply cannot give. He'll not change, not in the time you have left together. You can, if you wish.
Take a good hard look at yourself.
I am going to go out on a limb here and say you, due to your current circumstances, are hunting more for reassurance and a feeling of safety and belonging. The Dad bit not Brad Pitt, if you will.
You want to be cherished before you have to leave, and, instead of turning to the one person you can truly rely on - yourself - you look for it from an outside source. That is not a good thing for you or for your partner. Not fair on either of you now, is it?
Now, as to what you do - well. You have 6 weeks left before you leave. You can split with him now, or you can simply enjoy your remaining time together without getting stressed about it and split when you leave with, no hard feelings and no regrets.
You are, from what I have seen of you, a tough, smart and compassionate lady. Apply a little of that compassion to yourself.
PS - rxy, I am sorry. Not neglecting you, I simply got nothing here for your situation. GBFF or RP might have better advice.