Unfortunately I think there is little you can do.
The photos were not taken surreptitiously. You took them yourself and sent them to this guy. That pretty much kills the invasion of privacy angle. You cannot have a reasonable expectation of privacy in what you knowingly expose to the public.
Has he doctored them or done something to them so that they do not accurately reflect you? If not you aren't going to be successful in some sort of false light defamation claim. If its you, its you. Unless he posts some sort of comment about you thats false, there isn't much you can do.
Did you have some sort of an agreement as to the use of the pictures? Based on your facts it does not sound like it. It would seem that you sent the photos voluntarily and without condition in the hopes he would like what he sees and would begin a relationship with you. That pretty thoroughly kills any breach of contract action.
And lastly, it does not sound like you copyrighted the photos before you sent them, so you don't likely have any leverage there. Even if you had, there would be hurdles here as well.
I'm sorry, but I think that you have little recourse.
I certainly disagree with the last poster. I would argue that the publication of those photos IS illegal, and that your guy-friend has committed the tort of invasion of privacy via publication of private facts. Here's how the Supreme Court describes the tort (civil wrong):
Applying existing California tort law, the plurality opinion holds that to establish a cause of action for invasion of privacy by publication of private facts the plaintiff must show that a private fact was publicly disclosed, that the disclosure would be offensive and objectionable to a reasonable person, and that the private fact was not newsworthy.
Shulman v. Group W Productions, Inc.
18 Cal.4th 200 (1998).
Go get him!
As a follow up, I would argue that the private fact was published when the poster sent them to the prospective beau. They were no longer private at that point. Again, one cannot have a reasonable expectation of privacy in something one voluntarily exposes to public inspection.