I think this is interesting. If you're genuinely trying to help your wife, then I do have some advice. I am a sexual abuse survivor and have PTSD. I will preface this by saying I'm going to be honest with you, so I hope that you will not be offended.
1. Please understand that all sexual trauma can cause similar reactions. It has little to do with how "severe" the abuse was. Being molested repeatedly is just as "severe" as rape in that sense.
2. Please understand that begging for sex can be seen as coercion. It seems you have a high sex drive. That your reasons for marriage weren't necessarily all that you loved her, but that she could have children and could have sex. That may not be your intention, but it comes across that way. That could be making her feel like a piece of meat. Therefore, triggers.
3. Sex drives in a PTSD sufferer change. For sexual abuse we can be super horny as a way to cope with what happened to us. To explore that freedom in a sense because our sex drives got engaged in a way beyond our control. It's a way to take it back for ourselves. Same with not wanting sex. It could cause tons of triggers. We may not be present enough, you would just be having sex with a puppet. I think you should ask yourself if you truly want intimacy with your wife or just to feed your sex drive at this point. You may be making her PTSD a lot worse and causing new triggers if you force her.
3. Screaming... It makes sense for her to completely shut down. It's called emotional abuse. This is something you've been working on and I commend you for that. I myself cannot stand screaming in the least bit. Its a trauma inducing situation. I have a no scream rule. I think it's wise what you are doing to not be with her if you think you can harm her even emotionally for a time.
4. Please understand, that PTSD sufferers are more sensitive to certain things. They need care, patience, love and understanding. They above all need to feel safe. If you find that your relationship is toxic, then yes taking time apart makes a lot of sense. I know it can be really hard. I think if you also find that there are things you can improve on, such as focusing on her needs and not just yours that could help. I think coming on here is a good first step at that. Plus, I recommend a 12 step program to base off of when dealing with things like anger management. Perhaps it could help you in the future and make peace with your wife.
I'm sure I didn't succeed in not being offensive, so I'm sorry if my intentions didn't come across well. Please know that though I am giving my honest opinion (not saying it's fact) that I am hoping for the best for you two, whatever path that takes you in. Good luck!