CielDuMatin has made many good points here and I'd advise you to give them close consideration. It concerns me that your girlfriend is so controlling over *your* behavior, but unwilling to make concessions to your requests about *her* behavior. I would want/seek a big change in that kind of relationship dynamic, if I was in it, or I'd want just plain out, but I'm not you, and I have different likes/wants/needs.
The important question I think you have to ask here is, are *you* happy in this relationship, just the way it is? If not, do you think you can learn to be happy in it? If you can't, do you think there's a reasonably good chance the relationship can change so as to allow you to be happy in it?
It's all about figuring out what you want or need, and what you can or can't live with. As for interacting here with other Polyamory.com members, I agree with CielDuMatin, you aren't turning your decisionmaking process over to a bunch of random strangers. You're turning to a polyamory-specialized community to get info and insight. The actual decisions you make will still be your decisions, and you'll be the one making them. So I don't feel that this somehow makes you "less of a man," but I do feel this makes you a "smarter man." Gaining learning and perspective is surely a good thing.
I guess it would be a first step if she would at least introduce you (to her FWBs) as a friend, though CielDuMatin is right in saying that still wouldn't be the honest kind of introduction she ought to make. You can always give the situation some more time and see what improves, and what you feel will (or won't) continue to improve.
Whatever you decide, examine the situation closely, and consider what would be right for you. Your opinions do count, you know.
Love means never having to say, "Put down that meat cleaver!"