Hi Thehopelessrunner. Welcome to Psych Central. I am sorry you are facing challenges to your marriage from the symptoms that you face.

There are no easy answers. Have you considered contacting a specialist in Combat PTSD? That sounds like a serious situation and an expert in that area with good track record could make your path easier.

These might be of interest
Coping with Combat PTSD

Borderline Personality: 7 Powerful Ways Families Can Cope With Traits | Caregivers, Family & Friends

Difference between PTSD reactions and Borderline Personality Disorder | The Exhausted Woman

Posttraumatic Stress Disorder (PTSD) | Psych Central

Paranoid thoughts can be distressing. One way a friend has learned to cope with them is to accept that maybe they are true, maybe they are false. Suspending belief helps them if they can find something else to focus on. Like putting those thoughts on hold "Paranoid thought, hold on for a minute, I will get back to you." Then try to focus on your room and see if you are safe in your room. They connect with the senses, and feel their breath. They can feel their heart beating. They see if they can connect with that safe feeling even for a moment. I guess this might be called mindfulness. More on that here:

Where Jon Kabat Zinn uses the term "pain" it may be worth thinking of this as trauma. It is worth a try.
YouTube

https://youtu.be/ss1_s5gajyY

https://youtu.be/iOo4ys0tqE4

Hope you find the support you are looking for.