Hey there,
It really sucks when things get stuck in your head, and it's not really because of
TH, but because you talked about them. You got to keep letting it out, talking and thinking it through, and trying to relax and get help, and then the thoughts go away. You could also try distracting yourself. But I have found, that if you keeping thinking about it, it really means you need to try to work through it, either on your own, or with help.
And yes, posts come up on google. However, as long as you do not put your last name, location, or e-mail address on the forums or your profile, the chances of someone finding you is slim to none. It can happen, but they'd have to be an extremely good guesser, and you could always deny it if you want.