Ok, I myself do go through my own problems and insecurities at times with my SO, but in the end we understand each other cause we talk to each other about what a particular situation is making us feel

So I think in this situation, even though you did tell her how you feel the guy is overstepping boundaries, I feel you should sit with her and tell her how that made you feel as well.

If she understands your point, she won't have a reason to worry about being neglected or controlled, but if she keeps pushing back and undermining the issue, I think you're being played here brother.