Welcome to the forum!
I'm so sorry you're going through all of this.
Please don't allow your position in the church to make you feel like you have to deal with this alone.
A church is supposed to be support, help and healing for the wounded: pastors, and their families included.
If your church rejects you, in your pain and struggle, it is not a church that you need to be in, and frankly, is not worthy to have you serve there. There are others that would be glad to welcome and embrace you in your pain.
You must have wise counsel, and not try to handle this alone.
It's very good that you've come here for advice and support.
I need to say that PTSD is a diagnosis - it's Not an excuse.
I have PTSD, and a slew of additional Dx's from trauma, and I choose to be loving, gentle, kind, and try my hardest to never, ever, ever wound anyone through my words, actions or inaction.
Do I get hurt or angry? Sure I do! But, I bring it into therapy to be discussed and dealt with in helpful, healing ways. No one ever gets screamed at, threatened, or harmed. I struggled with suicidal issues for a long time. I took that pain into therapist's offices and to hotlines to learn how to cope in healthy ways with that level of pain. It was my choice to not burden, threaten, frighten or abuse my family or friends with suicide thoughts or outright threats.
Your wife isn't helpless, even if she was trained in helpless thinking. She has choices as to how she deals with her illnesses.
You have some choices to make, as well. Please work with wise, compassionate professionals. The biggest responsiblity you have is to work carefully to decide how you, helping professionals and your wife can best protect and help the children. You also must take good care of yourself, because you are needed, and must be able to function well. Reducing stress, eating healthfully, getting good rest (a positive aspect to your sleeping in separate rooms), quiet time in prayer, fellowship with fellow, trusted, pastors. Do not, while still married, find comfort from another woman. That temptation is likely to strongly come out of nowhere. Adultery would steal your children, ministry, good reputation... Hang tight onto God and please seek out all the support and guidance you can from trained and wise counselors.
I hope you can get your wife into good trauma counseling. Your entire family would benefit by her being in therapy with good trauma counselors. There are good Christian ones, but please don't be afraid of Counselors who are not Christian. I've been working with Christian, Jewish and Buddhist trauma counselors, and they have been powerfully gifted and beautifully trained in this work, and bring valuable insight and healing. You need the best that you can access.
There is much more, but all I can write, for now.
I will keep you, and your family in my thoughts and prayers.
With my deep respect and concern,
Deer
P.S. I see your post above. That's good that you have custody and she is a stepparent - that's a "relief", in case you need to separate or divorce again. I'm so sorry you're going through all of this.