McIlroy has not celebrated a major since winning his fourth at the 2014 PGA Championship and the Northern Irishman admitted answering questions about his barren run at golf's biggest events is exhausting.
"It is, but at the same time when I do finally win this next major it's going to be really, really sweet," McIlroy said after finishing one shot back of Wyndham Clark.
"I would go through 100 Sundays like this to get my hands on another major championship."
The world number three started the final round at Los Angeles Country Club one shot back of co-leaders Clark and Rickie Fowler and ended up in a two-horse race on the back nine.
He was ultimately undone by a putter that went cold and a misjudged wedge shot at the par-five 14th, where his third disappeared into the face of a fescue-guarded greenside bunker.
McIlroy called for a ruling and got a fortunate break as he was awarded a free drop but was unable to save par.
"I feel like I didn't time the shot perfectly. I hit it when the wind was at its strongest and the ball just got hit a lot by the wind, and obviously it came up short," said McIlroy.
"If I had it back, I think I had the right club and the right shot. I might have just had to wait an extra 15 or 20 seconds to let that little gust settle."
While McIlroy's hopes took a severe blow on that hole, he still had a chance to get into a playoff after Clark bogeyed the 15th and 16th holes but the American sealed the title with a solid two-putt par from 60 feet at the last.
"You don't want to wish bad on anyone, but you're really hoping for a three-putt. You're hoping to somehow get into a play-off to keep giving yourself a chance," said McIlroy, whose sole birdie of the final round came on the first hole.
"You're rooting for one guy, and that guy is yourself at that point. I guess you're just hoping for the other guy to slip up or make a mistake or give you a glimmer of hope."
Despite falling short, McIlroy took comfort in the fact that he executed his gameplan of hitting fairways and greens all week even though his speed control with the putter was off a touch over the final two rounds.
"Fine, fine margins at this level and at this tournament especially, but I fought to the very end. I obviously never give up," said McIlroy, who will get his next shot at an elusive fifth major at the July 20-23 British Open in Hoylake.
"And I'm getting closer. The more I keep putting myself in these positions, sooner or later it's going to happen for me. Just got to regroup and get focused for Hoylake in a few weeks' time."
