"After a few days or weeks she calms down, apologises and goes back to being her normal good self. She stops shouting at me, drops the snide comments and allows me to touch her again. We get on well for a few weeks until I start to notice the fear/tension building inside her again. Eventually she blows up over what is usually an insignificant matter (like me forgetting to take my mobile phone with me when I go to the grocery store) and the whole cycle starts again."
I hate to say it, but your description of your wife reminded me of what my husband puts up with in our marriage. I am a diagnosed severe PTSD sufferer and military trauma survivor and I suffer from nightmares, black-out rage, blow-up anger, fear, paranoia, hyper-valiance and all the works. The cycle you narrated above, the fear/tension building, the sexual aloofness, the rage and emotional outbursts followed by a week or a few days of calm, usually precipitated by a build up or "boiling over" of the anger are exactly what I suffer through on a week-to-week, month-by-month basis. My poor husband is just as kind, patient and gentle as you are and he watches -and endures- my PTSD cycles the way a farmer dreads a hail crop to his farm.
Believe it or not, PTSD is very curable, though it may take years of therapy and education for your wife to recover and for your marriage to function more smoothly. Getting therapy from a proffesional that specalizes in PTSD, particuarly in the trauma-related area in which your wife suffers, is the first that you need to do. The second is to get a marriage counselor (not her therapist) and/or find a support group for yourself. Reading up about PTSD, the affects, the cycles, symptoms and causes will also be helpful. Some of the things my husband did to help himself cope with my PTSD are listed below. Here are some must-do's if you are suffering to understand why your wife is acting out...
1) Know Her Demon. What caused your wife to have Post Traumatic Stress Disorder? People aren't born with PTSD. They experience a horrific or unnatural event that shocked their bodies, mind and soul. They are in a constant state of trying to cope with an un resolved past. Likely your wife is a survivor of sexually-related trauma. Learn more about her trauma, if she was abused, by whom, when and under what circumstances. The more knowledge you have about your wife's PTSD and her past the easier it will be to understand what is going on in her head and either remove triggers or anticipate blow-ups.
2) Safe-Talking. If you can make it through step one and get your wife to confide her past and PTSD cause with you, congrats, you've achieved something most spouses of PTSD sufferers struggle to accomplish. Most likely your wife can barely articulate her painful-past to herself and feels shame, guilt, helplessness and un resolved anger. The more you can get her to dialouge about the trauma in a normal setting, before or after the "blow ups" the better. PTSD survivors need to retell their story over and over to a kind and compassionate audience or loved-one. This helps them to re-associate their memories, to recognize that they are not at fault for the trauma, to regain dignity and helps them to overcome shame. Don't be surprised if once you get her to recount the past she will start "remembering" things she forgot and telling you about it. Memory loss is very common with PTSD survivors and probably one of the main reasons they blow up. The more she can remember and talk, the easier it will be for her to control her panic attacks, her rages, her mood swings etc.
3) Identify the Cycle and Cyclic Triggers. Since I am often unaware of my thoughts or dissociated from my feelings due to stress and hyper-vigilance, I cannot identify what 'sets' me off. My husband, however, has been able to observe what "triggers" my outbursts. In my case, a man staring at me the wrong way, an unexpected knock on the door, fireworks etc all "set" me off and cause me to panic, break-down or explode. I imagine the same goes for your wife. While she is carrying on with her day, whether it is good or bad, her unconscious mind is processing her environment around her in an attempt to identify danger signs. These danger signs are associated with her past trauma eg(sexual, psycho-emotional, combat, trauma related). Try to identify what her blow-ups are linked to. Is it related to a messy house? Nightmares? Her mother's phone calls? Any one thing or event can be the "trigger" point of her emotional outbursts if it precipitates a painful memory or is any way linked to a pattern of past trauma.
4) Finding her Calm Point. When your wife "revs-up" for one of her PTSD blow-ups, whether it is a rage-out or an emotional spill, be prepared to listen, soothe and comfort. Raging PTSD sufferers are experiencing intense emotions that they are disconnected from or cannot "feel" or emote due to being dissociated or feeling unsafe or unable to express them. Your wife's rage is really a mask for her hurt, fear and insecurities, however in most cases of PTSD sufferers, there is usually a calm point which will make her "reconnect" with her emotions and cause her to cry, emote or break from her anger. This "calm point" can be a number of things, from hugging, massage, encouragement, cuddling with a loved one/pet animal etc. For me, my calming point is when my husband takes me in his arms and rocks me back and forth and strokes my head. I am usually so angry and confused I get a migraine. Once he begins to physically touch me and stroke my head, I go limp and cry as I begin to feel safe and emote. Creating a safe-spot for emoting will help your wife to feel free to cry/emote rather than rage. For me, it is the bed. No matter what happens I know that the bed is the "hate free zone" in our house. No words of criticism or anger are spoken while someone is on the bed. I simply go there, pull the covers over my head and begin to cry. This is a signal to my husband and everyone else that I need time-out. Provide your wife with a similar calm-point and safe-space because likely her rage is a mask for the grief, hurt and pain she cannot allow herself to feel in the moment.
5) Boundaries. This is probably the most important thing you can do for yourself and the children should you have them. Establish boundaries, both emotional and verbal. If your wife is using you as a punching bag you not only need serious therapy as a couple, you need to establish firm boundaries. Talk to her while she is NOT in one of her PTSD rages. She needs to be calm and otherwise stable when you approach her with your list of boundaries. The number one boundary needs to be personal respect. Let her know that any anger she directs at you, the criticism, blame and rage is inappropriate and hurtful. Put your foot down. Make a consequence attached to the boundary and enforce it. Eg. You are going to a concert and the traffic makes you late, your wife rages "it's all your fault, you should have planned this better." (Previously you would have warned your wife of a boundary/consequence "if you blame me for another thing out of my control or rage at me again, no matter what we are doing I am going to leave for 30 minutes. Only when you are calm will I engage with you about this again.") Remind her of your boundary and consequence and simply enforce it. Only when she realizes you are serious will she begin to attempt to control or redirect her rage in an attempt to avoid the consequence. Too often PTSD sufferers are catered to because people feel sorry or guilt ed by their pain and anger. The best thing you can do for your wife is force her to deal with her PTSD symptoms by protecting yourself. If she really cares for you she will do what it takes to protect you from her PTSD anger-related behavior.
There are so many resources to help you. Wish I could just tell you that as a wife with a husband like you, recovery is possible. You can get through this and enjoy a happy marriage. It gets better with help. Therapy and Chakrah, weed and PTSD service dogs are helpful tools that can aide you. Wish you the best