Montag tells Mildred, "I need you so much right now. . . ." What does he need? What is he seeking to attain with his wife?

After Captain Beatty leaves Montag's home, Montag shows Mildred his secret stash of books and begs her to help him read them in the hope of finding some significant, life-changing information. Montag pleads with Mildred to look through books in order to attach meaning to their superficial, shallow lives. Montag recognizes that his marriage is failing, Mildred will eventually commit suicide, and he will continue embracing his meaningless, unfulfilling life if they continue down the same path.
When Montag tells Mildred that he desperately needs her right now, he is hoping that his wife will acknowledge his thoughts regarding their marriage and superficial life, which will motivate Mildred to look to books for answers to life's most pressing questions. Essentially, Montag is attempting to influence his wife to read books with him in order to alter the trajectory of their lives.
Tragically, Mildred refuses to examine herself or engage in intellectual pursuits. She seems perfectly content watching her interactive parlor walls, listening to her Seashell radios, and self-medicating.