› firstname.lastname@example.org 
I was on antidepressants for a year and just came off them recently. It was situational; I have no other psych history. I've always fantasized about being submissive but never seriously acted on it. But since I've been off the medication, I've experienced an intense surge of sexual interest. I've developed an online relationship with someone in which I am his sex slave–toy. I've just sent him some pictures of me. I'm a professional and my friends and family have no idea.
I feel I'm about to go out of control with this desire. Out of control is bad, but is being a sex slave bad? I need to either find a safe place to act out my cravings or go to counseling. How do women who want to be submissive slaves become so safely? What the hell is wrong with me?
In my little subcultural corner over here, not a thing, but I wouldn't be so sanguine about it if I had evidence that you wished yourself harm or were not, as they say, tall enough to ride this ride. You seem a cautious, even somewhat timid sort of girl though, and while that might hold you back a bit, it's better to be held back than to hurtle blindly over a cliff.
I know a couple who established a relationship like yours, never intending to meet, let alone fall in love, and last time I heard, they were living on a boat and raising kittens. That's rare though. More typically, what happens online ought to stay online, if you ask me. I don't mean online dating; that's fine, but if you've established a master-slave deal with this guy based on nothing but, well, mastery and slavishness, what are the chances you are otherwise compatible?
Keep Mr. Web Master–your Web master as a toy (he's your toy as much as you're his) and start from scratch. If you're not out trolling for scary strangers who could actually hurt you and you're not being driven so crazy by twisted desire (can't you see the pulp-style illustration?) that you can't maintain your respectable, professional standing, you don't need counseling. You need to read some books (not the pulp kind, the kind they sell at nice sex stores), join an S-M educational group or attend some "munches" (coffee klatches for would-be perverts), and start experimenting with being the sort of sex slave who sheds her collar after a couple hours and goes home and feeds the cat. This sort of program, entered into knowledgeably and pursued in moderation, ought to get you where you want to end up: as a "slave" who commands respect and controls her own destiny. There's no such thing in real life, but this is hardly real life, and that's the point.
I'm not-so-recently divorced and starting to think about having sex again. My problem is, whenever I start thinking about sex, it's memories of what my husband and I did (mostly BDSM) that come to mind, and I just shut right back down because I don't want to think about him. Do I just need to buy a bunch of random porn and hope I'll light on something else that arouses me?
Long Dry Spell
Not a bad idea, but you don't have to buy anything. (You really have been gone awhile, haven't you?) Porn is free for the finding all over the Internet, and you should be able to find representations of not just BDSM scenarios but the exact BDSM scenarios you used to act out with your husband — minus the husband. Looking at or reading some of this stuff may not fully exorcise your husband's unwelcome ghost — it probably won't — but it is sure to help. BDSM also, unlike other sexual proclivities, has the advantage of being a spectator sport. If you live in or near or can visit a major metro area — the kind that can support a leather shop or two and has a gay pride parade featuring humans, not golden retrievers, being proudly leash-walked through the center of town — there will be some sort of club or private party circuit where you can see S-M in action. The disadvantage of live display is that the people are unlikely to look as good in leather panties as do the models on the Internet. Plus, you have to be polite to them and ask if you can watch — in short, you have to talk to them. The advantage, of course, is that you do have to talk to them and thus might make a friend or find someone who is neither your husband nor the ghostly afterimage of your husband with whom to do S-M. This is all very hard work, and for the confirmed introvert it (speaking) will never come naturally. But compared to being alone, lonely, haunted, and unable to masturbate, it's got to be a breeze.