Episode 47: When someone with PTSD pushes you away, you need to know what to do because it is so painful. Dr. Daniel Williams, MD discusses this difficult topic, as it is the most often asked regarding PTSD.
How to Help Someone with PTSD when the Push You Away

Don't chase them.
Your story is safe.
Start with Your Strength. Many prefer a non-threatening course like the Sex Therapy or Pet Therapy courses that come with membership.
Don't feed into unhealthy behavior.
Don't be an enabler.

What Not to do after PTSD
This is an entire chapter in the very first book I wrote (Combat PTSD in America: Toward a Permanent Solution) as Chief Resident at Baylor Scott & White, which is available as PDF in the Mental Component course.

Put a time limit on grief.
Assume anything, especially that someone will be better if they talk about it.
Stick exposure therapy up your assessment.