Living with fear of one's safety for a long period of time can lead to a person developing PTSD. You have also described how your husband is constantly a worry about what new trauma will result with a seizure and that you have to literally worry about that every day, and this has been for a prolonged period, you don't have a chance to just feel safe, you are always vigiliant, hyper vigilant. Yes, that can lead to the anxiety disorder called PTSD.