Stosur was livid to have committed 34 unforced errors during her 3-6, 4-6 loss to Sharapova in one hour and 40 minutes.
"I felt really good going into it," Stosur told reporters. "I'm just incredibly angry with myself right now that I wasn't able to do more and give myself more of a chance to really feel like I was in the match.
"It was all round a bit sloppy. Never really felt like I played really well for long period of the match.
"Never any momentum, never any rhythm or anything to the match. It was incredibly frustrating."
With her French Open campaign over, Stosur has now set her sights on the grass court season after securing a Wimbledon seeding with her first title of the season at Strasbourg last week.
"My tennis the last month or so has really picked up," she said. "If I look at it from a bit more of a broader picture, things are moving in the right direction again, which is a good feeling.
"[I] feel like I'm playing a lot better at the moment, so that kind of makes today even more annoying.
"Look, it is what it is. I'll be ready for the grass and then for the rest of the year."