What is the best martial art to study if you have PTSD?
I suffer from freezing. Im not sure if that narrows it down. But based on how many martial art disciplines you studied do you recommend any discipline to help beat this particular symptom?
My immediate impulse is that you're going to want to avoid styles that are high-stress or emphasize more combative practices. Your ideal martial art might be something non-contact, practiced individually. My first recommendation would be Tai Chi. It's a soft style, generally doesn't involve fighting an opponent, and is often reputed to be good for stress.
My second recommendation would be Capoeira, particularly if you can find an Angola group. While Capoeira is a bit more physically active, it also has very strong play and musical components. The "sparring" in the roda is competitive, but it's generally played without contact, and the emphasis is on demonstrating skill rather than scoring points via contact, so when you're faced with a superior opponent, the odds are that they'll be using their skill to mesh with your movements to make the game look more impressive rather than beating you down to show how superior they are.
Based on the clarification you gave here that your primary problem is "freezing", I would recommend Tai Chi. There, there's very little external pressure, and the worst that could happen if you freeze up is a pause in the form versus possibly missing a dodge or falling from a precarious position.