Do you think that Holdon had any serious feelings toward Jane Gallagher? Was she an ideal for Holden?
Seems more like Holden simply had such a deep fear of maturing,growing out of his "rebellious" stage and facing the world as it is, that the only thing that made him "happy" was anything that reverted him to that stage of his life when he was younger and carefree. Each time he mentions Jane, it would be referring back to those times, for example, when he says
“We’d get into a god dam movie or something and right away start holding hands, and we wouldn’t quit till the movie was over. And without changing position or making a big deal out of it. You never even worried with Jane, whether your hand was sweaty or no. All you knew was you were happy. You really were”.
Another clue to this is that he always thinks of her when times get rough. Yet, he does not make the attempt to contact her. Why? Because he knows it is not "the" Jane that he would remember from his younger days, but a woman who has indeed matured and moved on, hence, he would rather keep the memories and summon them all the time rather than, again, face the world for what it really is.