By Tony Jimenez

WOBURN, England (Reuters) - Cristie Kerr has bagged more than $17.5 million in career earnings, won two majors and three times occupied top spot in the world rankings but this season has been an 'annus horribilis' for the American.

The 38-year-old from Florida seems completely incapable of finding the fairway off the tee and her chronic problems with the longest club in the bag are beginning to get her down.

"I thought the weather was nice this week," world number 21 Kerr told Reuters through gritted teeth after plunging to a seven-over-par 79 in the final round of the Ricoh Women's British Open on Sunday.

"Are you ready for a cocktail yet?," she then asked of fellow countrywoman Brittany Lincicome as her Solheim Cup team mate walked past.

Kerr, who topped the rankings three times in 2010, appears as though she is at the end of her tether with her PXG driver.

"I've just been struggling with it all season and I don't know if I'm going to get it worked out," she added after finishing way down the field at the Woburn major on 296, eight over.

"I've been using a new driver this year and I can't seem to get a consistent miss out of it.

"I'm now on my sixth different driver. I've been trying really hard, no one's trying harder than me to figure it out."

Everything looked rosy in the garden for Kerr in November when she claimed the 18th LPGA Tour title of her career, and a cheque for $500,000, after winning the end-of-season Tour Championship in her native Florida.

VERY FRUSTRATING

The eight-times Solheim Cup player is used to featuring high up on leaderboards but 2016 has almost been a barren wasteland in terms of good results, a tie for eighth place at this month's U.S. Open representing one of only two top-10 finishes.

"I've never experienced anything like this in my life and it's kind of disheartening and very frustrating," said Kerr of her driving issues.

"It kind of bleeds into the rest of your game too because you are always struggling to get it on the green and make your pars instead of normally when you're on the fairway, you're trying to make birdies.

"I don't need to revamp my game, I just need to find a driver I can hit on the fairway," added Kerr.

"It's starting to seep into my self belief a little bit and I know that's not me. Historically if you look at my seasons for the last 15 years, this is completely out of character."

Kerr, who won the U.S. Open in 2007 and the PGA Championship

in 2010, is now pinning her hopes on the manufacturers finding a solution to her driving problems.

"I've got a three-week break from the game and hopefully I can try and work it out," she sighed. "I've put my faith in PXG and hopefully they can figure it out for me.

"You can hit anything on the range but once you get into competition it changes. I've just got to go back and tell them what's going wrong again and go back to the drawing board."

(Editing by Ed Osmond)