While I'm still recovering from the other trauma... I just want you to know - No matter what happened, don't just blame yourself.
I did that in the past and I got always sick because of it. But now... I don't do that anymore, unless I do really know that I'm also partly responsible for the consequences. You won't get anywhere if you just blame yourself. So, stop blaming yourself if you're not responsible for it. But don't also blame the others for your misery. If you want to feel and get better in life - Take action. Every great leaders will say that. I'm talking here about our Personal Freedom. I've learned this words from Brendon Burchard's book 'The Motivation Manifesto' and Brian Tracey.
Let's get back to the topic for a little bit (Self-blaming). Most of us are likely going to blame themselves because of something that happened to them. For example, I blamed myself in the past for being unable to warn my parents about the molesting case at the beginning. If I had warned them about that, they/I could have prevented the assaulting case. Yes, I got molested for days at the beginning and then assaulted. I was really powerless back then. I got lured by the food he was giving me and he succesfully earned my trust.
I was ashamed and blamed myself for years. I couldn't even interact with the opposite sex properly. But then I got a calling in my head after that. That was when I began to open up to my little sister. I just shared my secret 2 years ago. I became the person I am today because of that calling.
In short, if you've regretted because of your unability to prevent something. You have to change the course in order to free yourself from it. This course will take some time and energy, but it's worth it. What you couldn't do back then, you can change it by doing it today, tomorrow or right now.
Good Luck! ;-)