Why does Holden want to take off with Sally now instead of after college? What is the difference in his eyes?please explain in detail

J.D. Salinger has created a classic character in his crafting of Holden Caulfield. One reason we could speculate that Holden wants to run off with Sally now rather than waiting until college is over is that he has no faith in the stability of the people he holds dear and thus tries to cling to them. Allie died. His older brother sold out to Hollywood. Even Phoebe is changing as she grows out of being the little kid he remembered. Another reason is his rapidly disintegrating psyche. Sally could be the life preserver he needs to keep from drowning. We know it won’t work, but for Holden perceives that she could be his “Catcher in the Rye.”