Both chainrings look pretty worn to my eyes. Is that a Shimano Chain as they may be directional with stamped markings on the plates going on the outside and inside plates should be mostly unmarked. If backwards the shifting is worse but the chainrings may be the main problem. Also if you want to get original replacement rings you can try scouring the net using every search you can think of. My friend has a 6700 groupset and I can usually find new-out-of-production parts if I spend enough time and wait till you find something reasonably priced rather than 3x the original cost which some try to get. Just found a brand new set of 6700 STI triple shifters for $160 on ebay about 8 months ago