I really need help, it's killing me.

So my girlfriend posted a picture, and I got jealous, so I told her about it, and we got into a little argument, nothing big, but she asked me if I wanted her to stop posting them I don't know what to say, if I say yes I'll feel bad like I'm controlling her, and if she still posts them I'll get jealous, any help?

It sounds like you don't want her to post any more pictures, so say so. Say yes, I want you to stop, but say it in a nice way, and let her know that you're not trying to be mean. Hope this helped a little, and good luck! :)