It's hard to think of separation or possibility of endings but rainbow the time has not come yet. Please don't fly off to this time in the distant(?) future. She is not gone yet and has further reassured you it is not for now. But the reality is, we are not eternal... And unfortunately, separation - in one form or another - is inevitable.

I don't mean to minimize what you're feeling but stay within the present. We never know what the future holds: of course you might resolve the attachment issues; you yourself might be more secure or independent, so much so that you wouldn't necessarily need her as much... new and stronger connections (whether platonic or romantic) in 'real' life might serve to fulfill some of your needs so that you won't feel the separation as such an agonizing loss.

It does not mean replacing her or other people becoming more important. I think she will always have a special place in your heart. And from what you write, i think you also hold a place in her heart... She might not want to work forever but hey, it doesn't mean she will wash her hands off you completely. You might forge a different relationship with her, so that she might still be in your life in some form (though no longer as your T).

Bottom line, don't give up hope. The story (of you and T) is not over. She's not giving up on you yet!