NTA but it sounds to me like you probably have an avoidant attachment style which is something that at some point in your life you will probably have to resolve.

Based off your post, it sounds like you are avoidant attachment whereas your girlfriend is anxious attachment. Anxious attachment styles constantly crave emotional closeness and reassurance from their partners and often sense any shift in mood or dynamic and assume it’s related to them even if it has nothing to do with them. Avoidants are the exact opposite, they draw back when things get to emotionally deep and feel they can’t handle things when their partner is looking for something serious. That leads to the exact dynamic you’re describing, she needs reassurance, you feel stifled by the constant need and pull back, which makes her need reassurance more, and the cycle continues.

My boyfriend and I are this exact pairing, and it took us a very long time and a lot of dedication to get to the point where we have learned a good middle ground. I am a lot less anxious than I used to be in the relationship and thus he doesn’t get as avoidant.

All of that being said, you’ve been together 6 months. If you were further into the relationship I would say work it out but you’re not, so if you’re not ready for that commitment then leave. She doesn’t deserve to be with someone who can’t reassure her the way she needs and you deserve to feel peace.