It's equally wrong to generalize that there's an air of sexist ass-hattery coming from the guys in this community...
... Have you been reading most of the relationship advice threads here recently? No, obviously not all men here are sexist asshats. There is a lot of asshatery going around right now, though. I'm tired of opening up threads and seeing "So, this girl is annoyed at me... is she on her period or something?" or "Oh my god, I can totally talk to normal people, but... I don't know how to talk to women!" And that's not even including the confirmed trolls, who were really horrible.
No, I'm not saying everyone is responsible for it, and the community is getting a lot better, but the life advice section in general has been making me feel a lot worse about being female in this place.
And before anyone says "just don't read it, then," that's not a viable solution, and you know it.
We're not saying you ARE desperate, just that you look desperate because you're off giving out all those material gifts. It's kind of like we would (often) say a girl is desperate if she has a lot of sex with a random guy who isn't committed, and what she wants is a long-term relationship.
I don't know that much about your situation from what you've said, but I'd say that you're getting too emotionally involved too fast, letting breakups influence you too much emotionally, and now... well, you aren't letting go. That's all right. I understand not letting go. But you might want to spend some time figuring out what you need to do to realize that you really don't want this girl back, to the point of it not mattering what she does with dudes in her spare time. Lesson learned, right? Now you don't have to deal with that bullshit again, so there's no point in putting yourself through it.
Well, anyway. It seems that you wanted to vent more than you wanted advice, so... do you have any questions, or are you feeling better? =)