Unfortunately, this isn’t an easy thing to fix after the damage is done.
The bottom line is: assume that anything posted to the internet is perpetual, and usually cannot be removed (even through legal action).
Somebody with malicious intent may use this to their advantage when trying to correlate your dating profile to other web content.
He or she will very likely check search engine caches for old pictures or bios that are easier to identify or contain embarrassing details.
You realized a few days later that it was too much of a privacy give-away, and made the wise choice to switch to a new photo. Search engines and archive sites are continually indexing as much content as they can from the internet.
These sites retain cached copies of images and pages long after they are changed or erased at the original source.
The second way your photos can betray your privacy is a bit more technical, but still terribly important to recognize.