Um, if you're getting fired for revealing your interest to co-workers that's discrimination. Its just like discrimination against someone who's openly gay. You can actually sue for that. Possibly with very little problem or effort on your behalf
Sorry, if this is off-track for this topic but the above paragraph is completely wrong from a legal standpoint. If you want to return solely to the topic of what the OP should do with his problem skip over this post.
1. If you get fired for revealing your interest to co-workeres that is not discrimination. There are many forms of discrimination: age discrimination, gender discrimination, disability discrimination, veteran status, race, ethnicity, and nationality among others. To treat someone differently because of any of these things is discrimination because they are a public component of one's identity. They are something that is perfectly acceptable to discuss at work and to make any sort of decision in the workplace because of them is discrimination under the 1964 Civil Rights Act otherwise known as Title VII. Talking about tickling with coworkers or sending emails about how you'd like to tickle someone, and how that would make you feel, is not a public part of your identity. It is a public discussion of a private fetish that is not appropriate for the workplace. It is completely unprotected behavior and most likely would be viewed as harassment by coworkers and employers.
2. Unfortunately, however, discrimination on the basis of sexual orientation is not a protected class under Title VII. Title VII does state that a person may not be discriminated in the workplace "because of sex" but neither the Supreme Court nor the lower Federal Courts have ever interpreted that language to mean because of sexual orientation. Of course states are free to pass more protective laws than provided by Congress, but few have done that.
Also, even if one were to bring an action for sexual orientation discrimination, it would not be because people merely said that person is gay. The plaintiff would have to show some sort of pervasive continuous conduct that was so severe as to create a hostile work environment. There's a famous Supreme Court case where the petitioner quit his job because he felt if he didn't two of his male coworkers would going to beat and sodomize him. If the conduct rose to that level and the plaintiff worker could articulate another reason for the discrimination besides sexuality, than it might be protected.
Sorry for the diatribe, but once upon a time I wrote a legal article on this topic, so I felt compelled to correct the assertions in that paragraph for those of you actually trying to learn something from this thread.
Now, as to the situation at hand, I agree with others that counseling potentially could be something to look into. But more simply than that, you are clearly in need of someone to talk to about your fetish. I understand the feeling of having your fetish get pent up until you think can explode. If you don't have someone to talk to or play with, that can be an overwhelming feeling. I would suggest getting more involved here on the forum; try making some contacts or friends. Talk with people in the chatrooms about tickling if you like, that's a much more appropriate venue than work. Whatever outward mode of expression you choose for dealing with it, do something so that you are never again compelled to talk about your private sex or fetish life in the workplace again.