You're not stupid, not at all. Actually, it is quite often for survivors to find themselves in the same situation more than once, for complicated reasons.

You are having these reactions because you are in a scary situation. Any person would be flinching and scared if their partner were violent against objects in the home and verbally abusive. Your history makes you especially attuned to it; the PTSD reactions are a way your brain and body are trying to protect you.

You are worth protecting. Do you have friends or family you can reach out to, in order to get more support and figure out what you want to do? Real time support is so important.

You're not stupid. Being in this situation has nothing to do with your intelligence. It stinks, but you a strong person who gets to choose what you do next, whatever feels right to you.