How to deal with ptsd

I ve been with my husband 5 years he suffers from ptsd. I m not really sure how to deal with it or even the right things to say But I feel like his ptsd is affecting our marriage. Hes distant he stay to himself alot and when he does talk he sometimes says mean things. I m heart broken because I wish I knew how to help him But he has mood swings here and there and blames me for alot of things its like Hes in denial.......I need help how do I deal with this