Your gf might have anxious attachment. Please look this up.

I was extremely anxious and clingy for the first 6 - 8 months in our LDR. At that time I failed to communicate my needs to him. Then I became more passive aggressive because my needs weren't met. At one point he said we might be not compatible with each other, etc etc because of my communication style so I did some reading on my attachment and try to self soothe. It worked eventually (took some time) and I no longer felt the need to get reassurance from him from time to time.

We broke up anyway but that was another story. I just feel that we have to self soothe ourselves. We cannot rely on our partner to get better. For example, if you are depressed please go to therapist rather than emotionally dumping on your partner.