Take the long view to save your marriage
Couples who have been together for a long time say the key to staying together is to work as a team toward the greater good, tolerating some tough (even tragic) times to grow together and work toward a mature kind of union.
Everything you report (pulling away, etc. after the trauma of your son's illness) seems a natural reaction to an incredibly challenging time. This is survivable, but you can't repair a relationship when you're on the fast track to dissolution.
You take the long view. You do not fill a giant void with dates. You fill the void with self-actualization. Be honest with your wife. Ask her to join you in counseling. If she won't go, attend on your own.

Sarra Sounds Off, Season 3, Ep 5: Top football teams in action and Nassau soccer playoff picks Gregg Sarra sounds off on Wantagh vs. Bethpage and Ward Melville vs Sachem North, plus Michaeil Sicoli has his Nassau soccer picks, an update on the high school fantasy football standings and the plays of the week.