My heart is breaking for you, for Jeff, and for your family. Jeff has been an inspiration to ALL of us here - and I'm sure he must be even more inspiring in person. We've told him that time and again, and he's always been humble and uplifting and humorous in his replies. He's fought the hardest battle of anyone here, always with a good attitude and spunky spirit, but I know his only regret is that he has to leave you behind and cause the grief you're feeling now. I'm sure he feels the same anticipatory grief that you do, which is only natural considering the wonderful love that you two have shared.
I know it is not much consolation, but the love you share with Jeff is something most people never get to experience in a lifetime. It is so special, which is also what makes it so painful to lose. I felt the same way when my mother was under home hospice care - the pain was unbearable, because the thought of losing the most precious person in the world to me was unbearable. People would say "At least you had that time with her" but of course, it's never enough. You just want it to go on forever, and it's agonizing. It's just not fair, it's just not fair that you should have to go through this, that Jeff should have to go through this.
Please believe the pain will get more bearable, and in the meantime, please come here to talk if you need to. And please know that Jeff's love for you is eternal and you can see it echoed in every thing he wrote about you. He adores you and you're the light of his life. Staying by his side and loving him is the best thing you can do and you're doing it so wonderfully. IT's okay to cry - he understands, and we understand.
Many cyber hugs and best wishes,